can I do Mage guild as well as house telvanni without them conflicting too much?

You can do both Telvanni and Mages. There is a late Mages Guild quest that requires you to kill some high level Telvannis but you don't have to do that quest, just refuse it.

As to living as a vampire - it is very difficult. You have to do without the majority of the services (travel, training, shops) NPCs will shun you, guards will attack you if you talk to much to them, you can't do quests - you can talk to members of the Mages Guild and Telvanni but you will get no work or help in the majority of cases. It is best to become a vampire, do the vampire quests and then take the cure so all is back to normal.

If it is really something you want to do you can get a helmet mod, and look into vampire mods, that's a common study

I have a vampire on Xbox and she is really fun to play. She killed Vivec and did the Morrowind Main Quest via Backpath. Yagrum made her the backpath Wraithguard and she was good to go except for the 200 hp she lost when she first equiped it. The main thing about playing as a vampire is that you have to prepare beforehand with several artifacts and enchanted items. Once you become a vampire no one will enchant for you.

Creeper and Mudcrab will trade with you. Forget Tribunal and Mornhold because nobody will talk to you there. You can do all of the Raven Rock Quests as a vampire but the trader I built there always tries to kill me. You can get the smith at Fort Frostmoth to trade with you only if you take the dry fort quest and do not complete it. (Keep some booze on you at all times and everyone at the fort will talk to you.) The smith at Thirsk will make you custom armor and trade with you. The Skaal will not have anything to do with you. ( They won't have anything to do with you anyway until you are into the Bloodmoon Main Quest) You can actually do a lot on Solstheim as a vampire. I guess the people there do not care if you are different. You can also take the boat to and from Solstheim as a vampire.

The vampires in your chosen faction will trade with you too. Do all of the vampire quests that you can do because you get some nice things by doing them.

I cant believe nobody's suggested http://planetelderscrolls.gamespy.com/View.php?view=mods.detail&id=771.

One of the best mods ever made. Even better when combined with scripted spells (i think). Lets you buy a 'transform into bat' spell. Very epic

:celebration: :celebration: :celebration:

As Rohugh already said most people will not talk with you and you can't travel by boat, gondola or siltstrider. Only members of the mages guild and Telvanni have no problems with vampires. You can even just do their quests and advance in ranks.
But that's also the only factions who allow that. The rest won't do that and you're stuck with the MQ. So you can do 2 things:
- Just as Rohugh said become a vampire, do their quests and then perform the cure
or if you want to live as a vampire, then first do everything what you want to do and become afterwards a vampire. In that case you can stay a vampire without any concerning about finishing the MQ and most other quests.

There are two mods to allow you to avoid all this. They help you conceil that u are a vampire, everybody will thus talk to you normally.

http://planetelderscrolls.gamespy.com/View.php?view=Mods.Detail&id=4133 by Yacoby
and
http://planetelderscrolls.gamespy.com/View.php?view=Mods.Detail&id=5676 by Alkrodion