Problems with mindmap

Question

I have two mindmaps in the following MWE and have a couple of problems.

The mindmaps are almost identical, but some child nodes appear at different positions, in particular Int.2, leaving different space with the right edge of the node, as indicated with red crosses.

Besides, no matter all the changes I introduce, I ALWAYS get the same overfull warning

 Overfull \hbox (7.53343pt too wide) in paragraph at lines 61--61

ALWAYS 7.53343pt too wide, no matter the changes I make, and I do not see any overfull problem anywhere...

I would really appreciate if someone could help. Thanks!

MWE:

\documentclass{beamer}

\usepackage{tikz,lmodern}
\usetikzlibrary{positioning,shadows,calc,mindmap,trees,shapes,
    decorations.pathreplacing}

\begin{document}



\begin{frame}

\begin{center}
\begin{tikzpicture}
    \node[inner sep=0, fill=yellow] (A) at (0,0) {
    \resizebox{.4\linewidth}{!}{%
    \begin{tikzpicture}
        \path[small mindmap,concept color=white!99!green, text=black,
        level 1 concept/.append style=
        {every child/.style=, sibling angle=-30}]
        node[concept, scale=0.8, font=\large] {BRCA1}[counterclockwise from=0]
            child[concept color=green]{node[concept, scale=0.6, font=\large] at(2,0) {Int.1}}
            child[concept color=green]{node[concept, scale=1.1] at(2,-.8) {Int.2}}
            child[concept color=green, opacity=0]{node[concept, star, star points=18, scale=0.6, font=\LARGE] at(1,-.5) {Int.3}}
            child[concept color=green]{node[concept, scale=0.7, font=\large] at(-.2,-1.5) {Int.5}}
            child[concept color=green]{node[concept, scale=0.5, font=\large] at(0,0) {Int.6}}
            child[concept color=green!25!white]{node[concept, scale=0.4, font=\LARGE] at(-3,.5) {Int.8}}
            child[concept color=white!90!green]{node[concept, star, star points=18, scale=0.4, font=\huge] at(-.5,1) {Int.9}}
            child[concept color=green!25!white]{node[concept, scale=0.6, font=\large] at(-.3,1) {Int.10}}
            child[concept color=green]{node[concept] at(0,2) {Int.11}}
            child[concept color=green!25!white]{node[concept, scale=1.3] at(1.5,-.5) {Int.13}}
            child[concept color=green, opacity=0]{node[concept, star, star points=18, scale=0.3, font=\huge] at(4,-.1) {Int.14}}
        ;
    \end{tikzpicture}
    }%
    };


    \node[inner sep=0, fill=yellow, right=.2cm of A] (B) {
    \resizebox{.4\linewidth}{!}{%
    \begin{tikzpicture}
        \path[small mindmap,concept color=black!90!green, text=white,
        level 1 concept/.append style=
        {every child/.style=, sibling angle=-30}]
        node[concept, scale=0.8, font=\large] {BRCA1}[counterclockwise from=0]
            child[concept color=green, text=black]{node[concept, scale=0.6, font=\large] at(2,0) {Int.1}}
            child[concept color=green, text=black]{node[concept, scale=1.1] at(2,-.8) {Int.2}}
            child[concept color=black!75!green]{node[concept, star, star points=18, scale=0.6, font=\LARGE] at(1,-.5) {Int.3}}
            child[concept color=green, text=black]{node[concept, scale=0.7, font=\large] at(-.2,-1.5) {Int.5}}
            child[concept color=green, text=black]{node[concept, scale=0.5, font=\Large] at(0,0) {Int.6}}
            child[concept color=green!60!black]{node[concept, scale=1.2] at(-3,.5) {Int.8}}
            child[concept color=green, text=black, opacity=0]{node[concept, star, star points=18, scale=0.4, font=\huge] at(-.5,1) {Int.9}}
            child[concept color=green!60!black]{node[concept, scale=1.1] at(-.3,1) {Int.10}}
            child[concept color=green, text=black]{node[concept] at(0,2) {Int.11}}
            child[concept color=green!60!black]{node[concept, scale=0.7, font=\large] at(1.5,-.5) {{\large Int.13}}}
            child[concept color=black!75!green]{node[concept, star, star points=18, scale=0.3, font=\huge] at(4,-.1) {Int.14}}
        ;
    \end{tikzpicture}
    }%
    };
\end{tikzpicture}
\end{center}
\end{frame}

\end{document}

Which produces:

Answer 1

For example, you could do something like this:

\documentclass{standalone}

\usepackage{tikz,lmodern}
\usetikzlibrary{positioning,calc,mindmap,trees,shapes,backgrounds}

\begin{document}

\begin{tikzpicture}
        \path[small mindmap,concept color=white!99!green, text=black,
        level 1 concept/.append style=
        {every child/.style=, sibling angle=-30}]
        node[concept, scale=0.8, font=\large] at (0,0) {BRCA1}[counterclockwise from=0]
            child[concept color=green]{node (int1) [concept, scale=0.6, font=\large] at(2,0) {Int.1}}
            child[concept color=green, text=black]{node[concept, scale=1.1] at(2,-.8) {Int.2}}
            child[concept color=green, opacity=0]{node[concept, star, star points=18, scale=0.6, font=\LARGE] at(1,-.5) {Int.3}}
            child[concept color=green]{node (int5) [concept, scale=0.7, font=\large] at(-.2,-1.5) {Int.5}}
            child[concept color=green]{node[concept, scale=0.5, font=\large] at(0,0) {Int.6}}
            child[concept color=green!25!white]{node (int8) [concept, scale=0.4, font=\LARGE] at(-3,.5) {Int.8}}
            child[concept color=white!90!green]{node[concept, star, star points=18, scale=0.4, font=\huge] at(-.5,1) {Int.9}}
            child[concept color=green!25!white]{node[concept, scale=0.6, font=\large] at(-.3,1) {Int.10}}
            child[concept color=green]{node (int11) [concept] at(0,2) {Int.11}}
            child[concept color=green!25!white]{node[concept, scale=1.3] at(1.5,-.5) {Int.13}}
            child[concept color=green, opacity=0]{node[concept, star, star points=18, scale=0.3, font=\huge] at(4,-.1) {Int.14}}
        ;
        \path[small mindmap,concept color=black!90!green, text=white,
        level 1 concept/.append style=
        {every child/.style=, sibling angle=-30}]
        node[concept, scale=0.8, font=\large] at (12,0) {BRCA1}[counterclockwise from=0]
            child[concept color=green, text=black]{node[concept, scale=0.6, font=\large] at(2,0) {Int.1}}
            child[concept color=green, text=black]{node[concept, scale=1.1] at(2,-.8) {Int.2}}
            child[concept color=black!75!green]{node[concept, star, star points=18, scale=0.6, font=\LARGE] at(1,-.5) {Int.3}}
            child[concept color=green, text=black]{node[concept, scale=0.7, font=\large] at(-.2,-1.5) {Int.5}}
            child[concept color=green, text=black]{node[concept, scale=0.5, font=\Large] at(0,0) {Int.6}}
            child[concept color=green!60!black]{node (int8x) [concept, scale=1.2] at(-3,.5) {Int.8}}
            child[concept color=green, text=black, opacity=0]{node[concept, star, star points=18, scale=0.4, font=\huge] at(-.5,1) {Int.9}}
            child[concept color=green!60!black]{node[concept, scale=1.1] at(-.3,1) {Int.10}}
            child[concept color=green, text=black]{node[concept] at(0,2) {Int.11}}
            child[concept color=green!60!black]{node[concept, scale=0.7, font=\large] at(1.5,-.5) {{\large Int.13}}}
            child[concept color=black!75!green]{node (int14x) [concept, star, star points=18, scale=0.3, font=\huge] at(4,-.1) {Int.14}}
        ;
        \begin{scope}[on background layer]
            \fill [yellow] ($(int8.west |- int11.north) + (-1pt,1pt)$) coordinate (c1) -- ($(int1.east |- c1) + (1pt,0)$) coordinate (c2) -- ($(int5.south -| c2) - (0,1pt)$) coordinate (c3) -- (c3 -| c1) -- cycle;
            \fill [yellow] ($(int8x.west |- int11.north) + (-1pt,1pt)$) coordinate (c4) -- ($(int14x.east |- c4) + (5pt,0)$) coordinate (c5) -- ($(int5.south -| c5) - (0,1pt)$) coordinate (c6) -- (c6 -| c4) -- cycle;
        \end{scope}

\end{tikzpicture}

\end{document}

Notice that the distance to the right edge from Int.2 is greater in the right hand map because of the starred node above. If you don't want that, you need to relocate that node. (Or extend the background of the left map.) This does, however, get the angles right as far as I can tell. That is, the two Int.2 nodes are aligned vertically which didn't happen when I ran your original MWE.