So my favourite chapter is Clear Sky and i decided to replay it. Before i only played vanila version.
http://www.moddb.com/mods/clear-sky-complete
Is this project the besto one?

I want bugs fixed, some content resored without altering too much.

i'd reckon so considering what you want, but as you've also played it through already, free sky is also worht a look (turns it into more of a sandbox world).