You can play with the vertical spaces. I defined all section commands new:
\documentclass{scrbook}\usepackage[T1]{fontenc}\usepackage[utf8]{inputenc}\usepackage[ngerman]{babel}\usepackage[automark]{scrpage2}\usepackage{xcolor}\usepackage{geometry}\geometry{a4paper, top=35mm, left=30mm, right=60mm, bottom=25mm, headsep=15mm, footskip=12mm}\makeatletter\newcommand\makeSecHead[4][\fbox]{% \@namedef{#2}{\@ifnextchar*{\@nameuse{#2@i}}{\@nameuse{#2@ii}}}% \expandafter\def\csname#2@i\endcsname*##1{\par\vspace{#4}\noindent #1{\parbox{\dimexpr\textwidth-2\fboxsep-2\fboxrule}{% \normalfont\normalsize#3\makebox[40pt][l]{}~##1}}\par\vspace{#4}}%% \expandafter\def\csname#2@ii\endcsname{\@ifnextchar[{\@nameuse{#2@iii}}{\@nameuse{#2@iv}}}%% \expandafter\def\csname#2@iii\endcsname[##1]##2{\par\vspace{#4}\noindent #1{\parbox{\dimexpr\textwidth-2\fboxsep-2\fboxrule}{% \refstepcounter{#2}\normalfont\normalsize#3\makebox[40pt][l]{\@nameuse{the#2}}~##2}}% \addcontentsline{toc}{#2}{\@nameuse{the#2}~##1}\par\vspace{#4}}%% \expandafter\def\csname#2@iv\endcsname##1{\par\vspace{#4}\noindent #1{\parbox{\dimexpr\textwidth-2\fboxsep-2\fboxrule}{% \refstepcounter{#2}\normalfont\normalsize#3\makebox[40pt][l]{\@nameuse{the#2}}~##1}}% \addcontentsline{toc}{#2}{\@nameuse{the#2}~##1}\par\vspace{#4}}%}\makeatother \makeSecHead[\colorbox{gray!30}]{chapter}{\Huge\bfseries}{20pt}\makeSecHead{section}{\LARGE\bfseries}{15pt}\makeSecHead{subsection}{\Large\bfseries}{12pt}\makeSecHead{subsubsection}{\large\bfseries}{10pt}\begin{document}\tableofcontents\bigskip\chapter*{Test unnumbered chapter}Text\section*{Test unnumbered section}Text\subsection*{Test unnumbered subsection}Text\chapter{Test numbered chapter}Text\section{Test numbered section}Text\section*{Test unnumbered section}Text\subsection{Test numbered subsection}Text\subsection*{Test unnumbered subsection}Text\end{document}
And here is some code for placing images without textpos:
\ifoot[{\makebox[\linewidth][r]{% \makebox(0,0){\put(10,200){\includegraphics[width=2cm,height=4cm]{tiger}}}}}] {\makebox(0,0){\put(-100,200){\includegraphics[width=2cm,height=4cm]{tiger}}}}