Do you want the HTC Sense interface? If not then you want an AOSP rom if so you want a Sense rom. Currently on the AOSP front I know people are running BlackAOSP 2.1 personal, CM7 (both 1.61 and 1.7), and ShiftTheory 2.0f. For Sense roms I can't really make recommendations I haven't run a sense rom for more than 5 mins in over 2 months.

You shouldn't need to change the radio but you can if you want. Since you are on MR2 it shouldn't matter if you flash the radio or rom first.

 

When you flash a rom a kernel will be flashed with it. You may wish to flash a different kernel to change battery life or allow easier over clocking later. I perfer the 3rd GB leaked radio, there is a link to it in the sticky. Radios that are MR2 and above will perform the same on any rom.

You boot into recovery by first going to hboot. Power off and then hold volume down while powering back on. Before you try this make sure there is not a zip on the root of your SD that is titled "PG05IMG.zip" or anything like that. If there is delete it.
Once in hboot you press volume down to highlight recovery and press the power button that will take you into recovery. I personally like TWRP more than CWM but CWM works fine.

 

You can also download an app called quick boot since you're rooted and use that to get to recovery. That way you don't have to go through hboot every time. Once you're on a custom ROM there will be an option to boot into hboot or recovery in the power menu (long press the power button>reboot)

 

There's some roms that say to flash a specific radio. Is that just "recommended " or required?

 

What radio are they saying to flash. If it is mr1 then forget the rom. If it is mr2 then it means mr2 plus.

Do you have an example

 

since radio flashing requires potentially dangerous hboot flashing,id prolly reccomend to stay where you are for now. as has been said,pretty much any rom worth running at this point will work with what you have. give it a few days and see how your voice and data connections are.

once youre a lil more confident you can try some newer radios if you want and see if there is any real improvement(i think alot of improvements,even those seen by me , are alot of times due to the "placebo affect" of something new,lol).

id also suggest checking out the thunderbolt rom list,and how to sticky threads at the top of the page. lots of info there. then post up if you have more questions about any of it.

 

The threads for the Eaton rom and lightning rom say to flash a radio. Eaton specifiea mr2 but the other one isn't labeled, just has a download link. I switched from eaton to Lightning and back to eaton flashing the radios each time.

 

Eaton is a MR2 based froyo rom I think. So any MR2+ radio should work fine. I know the dev says otherwise and it could be an issue with GB radios on Froyo but I haven't heard of anything like that happening before.

I am not sure what lightning rom is. Tesla Coil? If it is the newest one RC3 then you should be fine with any MR2+ radio. I would suggest if you are going to stick with Froyo to do so and not to flash in hboot so much, if something were to bork up in hboot you would have an issue. I personally would suggest you jump to a GB based rom. They are as stable as Froyo based, you can get the newest radios and stick with them without fear that the radio isn't going to work with a rom.