What limitations does rooting and/or installing a ROM put on my phone? I have an Evo and I'm kind of frustrated at the space limitations on the internal memory, the crapware that came pre-installed (Blockbuster and Nascar, Really?) and some performance issues.  I was thinking that the right ROM might solve those problems.  It seems like I read somewhere a while back that rooting/ROMs cause some dealbreaker problems that I didn't want to have.  I can't find that article again, so I figured I'd ask you.

If I root my phone and install a custom ROM, can I:


Use the Android Market like normal?
Use the standard GMail, Google Maps, GTalk, and other social networking apps without a problem?
Use the Google Voice app fully integrated like I do on the stock ROM?


I know this will void the warranty.  Are there any other limitations I should be aware of?
I can't speak for the Google Voice App being fully integrated - I only use it for the voicemail feature.  However I have a fully rooted Evo (Fresh Rom 3.5) and I still have access to the market and all the normal Google Android Apps.  In fact I find that rooting gives me more features like free wireless tether and with Fresh 3.5 the power manager is integrated into the notification drop down (which I find really cool).  Google Voice still works perfectly for voice mail.

As far as I know the only limitation is the one you have listed: it will void the warranty.  However if something goes wrong there is a huge community over at XDA to help you out or you can unroot and see what happens when you bring your device in to Sprint ( I haven't had to do this yet so I can't speak on that part).

Rooting (for me) has also made my battery life WAY better and gotten rid of those Sprint apps that I don't want.

Edit:
I can't comment on eldarerathis's post otherwise this would have gone there: I had forgotten about hardware limitations of using AOSP Roms like CM.  eldarerathis is correct though that with certain roms HDMI and 4G won't work.  When I had the HTC Hero and first loaded CM I think the Camera didn't work but in time this was fixed and this is why I have avoided the CM Rom so far for my Evo.

If you want the HTC Sense experience though don't go with CM or AOSP roms - these are essentially stock Android.

Hope this helps