As far as code formatting style (whitespace, tabs, where braces go, etc.) you should follow the prevailing standard in the code. If there isn't one, I don't think they have much to complain about. When it comes down to it, whether you put braces on their own line or not, put spaces around method parameter lists, etc. is personal preference, and you should yield to the prevailing style because in the long run, it really doesn't matter. What matters is being consistent.
When it comes to checking code into SVN, I would try evangelize what I feel that my way of doing things is the right way, so I would push back against people telling me to do something differentlythings, rather than letting myself be steamrolled. I don't check my code in unless it builds and passes tests, and if I'm making several unrelated changes, I break my work up into several commits. If something will be broken for a while, I create a branch and do my work there. Commits get descriptive comments. This works better in my experience than the "check in a pile of changes on Friday at 5:00" method, and it seems to be the prevailing "best practice" according to most of what I've read here and elsewhere. If someone has a problem with that, I would try evangelize what I feel is the right way to do things, rather than letting myself be steamrolled.