We have a new moderator at these forums who is a stickler about following the rules and guidelines of the forums found here:
Android Forums - Announcements in Forum : Verizon Fascinate Rooting, ROMs, and Hacks
One of the forum rules is pretty much posting questions in an already existing topic appropriate thread rather than starting a new thread which unnecessarily inflates the size of the forums. He is doing a great job of cleaning up the forums and moving new threads to an appropriate existing thread, so yours may get moved, may not, it's up to him. I will tackle your questions though.
1)The flashing in and of itself does not wipe data and contacts. You have to do a wipe of data, cache, and dalvik cache through cwm when going from Eclair (EA28) to Froyo (EB01.) You can use backup assistant on you phone to backup your contacts on your phone, or you can sync your contacts to your gmail account and restore them from there, or you can export your contacts to your sd card and import them back from there (the wipe does not touch the sd card.)
2) Yes, you can flash sc 2.8 over EA28. Yes you are going to another kernel, but the new kernel is included in the ROM. The thing is though you can't just flash the ROM, you also have to flash the EB01 modem. If you want to flash the ROM (which is found in the first post of this thread) by itself through clockworkmod recovery, you will also need to flash the EB01 modem which can be found here:
http://forum.androidcentral.com/ver...ckwork-flashable-froyo-eb01-root-busybox.html Or you can just use one of DroidXcon's all-in-one ODIN packages located here:
http://forum.androidcentral.com/ver...ged-roms-w-root-clockwork-updated-3-04-a.html Use the EB16SC28_DXC.tar and it will wipe your phone for you, you will get sc 2.8, the modem, clockworkmod recovery, and keep your root.
EDIT - Look at that. As I was typing our wonderful moderator moved your post to the superclean thread so I edited my response slightly.