Remove title and name from sidebar yet keep them in the bottom part of the presentation

I don't know what you mean about the footer since there is no footer in the PaloAlto theme. But for suppressing the title and name in the sidebar one needs to alter the template. Just add

  \makeatletter
  \setbeamertemplate{sidebar \beamer@sidebarside}%{sidebar theme}
  {
    \beamer@tempdim=\beamer@sidebarwidth%
    \advance\beamer@tempdim by -6pt%
    \insertverticalnavigation{\beamer@sidebarwidth}%
    \vfill
    \ifx\beamer@sidebarside\beamer@lefttext%
    \else%
      \usebeamercolor{normal text}%
      \llap{\usebeamertemplate***{navigation symbols}\hskip0.1cm}%
      \vskip2pt%
    \fi%
  }%
\makeatother

some when after you loaded the theme. It redefines the original definition. (I just striped the two blocks with title and name.)

Just taking the solution of boodworks to clean the autor and title of the side bar, before of PaloAlto theme you can add an outher theme as shadow to have these elements at the bottom:

\documentclass{beamer}
\useoutertheme{shadow} 
\usetheme{PaloAlto}
\title{The title}
\author{The Author}

\makeatletter
  \setbeamertemplate{sidebar \beamer@sidebarside}%{sidebar theme}
  {
    \beamer@tempdim=\beamer@sidebarwidth%
    \advance\beamer@tempdim by -6pt%
    \insertverticalnavigation{\beamer@sidebarwidth}%
    \vfill
    \ifx\beamer@sidebarside\beamer@lefttext%
    \else%
      \usebeamercolor{normal text}%
      \llap{\usebeamertemplate***{navigation symbols}\hskip0.1cm}%
      \vskip2pt%
    \fi%
}%
\makeatother
\begin{document}
\section{Section Test}
\begin{frame}{Frame title}
test
\end{frame}
\end{document}