Hello, ramonjosegn,
I feel your pain, really, the main reason to decide to develop a caching plugin is because of my personal experience with such plugins, which just does not do what they suppose to do.
Currently rewriting of .htaccess file is not necessary, the plugin does not use the technique other caching plugins use, it works at very last stage of page generation. Rewriting rules of .htaccess file are primarily used to deal with permalinks structure in WordPress (and sometimes for pointing to the cached resource files – CSSs or JavaScripts – and this is the reason websites to break honestly, if not done properly). However the Easy cache plugin does not minify external resources, like CSS or Javascript, it only save and minify the generated page/post/link/etc… as regular optimized HTML file (with all links inside to resources untouched, no combining whatsoever).
I plan to extend the plugin, so the next version 0.2 will include CSS minification and combining, although I`ll try develop it in such way, that not to require .htaccess file modification, because in general this is something which should be avoided by plugins, in my opinion, unless is absolutely necessary.