GENERAL
1. Would you say the army lists are somewhat balanced? yes, the rulebook lists (and swordwind) have issues, but if you hunt around for NetEA lists, the approved lists are very well balanced
2. What armies are overpowered in your opinion? none, some are difficult to play against as a beginner or with certain armies (in general tyranids can struggle against eldar for example)
3. What armies are underpowered in your opinion? again none of the NetEA armies are particularly underpowered
4. How different are the rules in the printed Epic Armageddon rulebook from those on GWs site right now? not hugely, just a few tweaks and clarifications in general, pretty much everyone on here uses the GW book with the 2008 update
SWORDWIND
5. Do people tend to play with Swordwind? in friendly games, sure, but I think most people here use NetEA or EpicUK lists, they're much the same, but with tweaks for balance and playability
6. How are Feral Orks faring compared to normal orks (esp. balance)? they do alright, I've only played against the epicUK list, but they seem fine
8. How are the Siege Masters list compared to the vanilla Imperial Guard list (esp. balance)?often considered a bit boring, but balance is fine, they tend to have a static playstyle, then sending out floods of light fast tanks to nab objectives
OTHER
10. Does it matter in terms of charging or other game mechanics if you use the square or the rectangular infantry bases? Any advantages of one over the other?you can string out the strip bases to cover more ground, can be important with scout screens.... I've seen people win tournaments with round bases however so it's not a huge handicap
11. Do you believe Epic will ever be back from GW?no, there is a possibility that it may come back in a limited release 'big box' format somewhere down the line (a'la space hulk and dreadfleet)
12. I know they are impossible to get these days, but anyone with experience with Tau?not as impossible as you might think..... they are a great army, lots of firepower and combined arms tactics (markerlights+guided missiles)
13. How would you rate the Warhound titans from Forgeworld vs. those on GWs site. Forgeworld Warhounds are actually cheaper as you get two.total no-brainer, the FW models are better in every way, the current metal warhound looks like a friday afternoon sculpt IMO...
14. There are soo many links, alone in this forum, too much stuff. I can't seem to find out what are official army lists, what are GW development army lists and what are community development lists.The NetEA compendium is a good starting point for all the community lists, all of the GW development lists have been continued in this supplement. EpicUK has their own set of lists for tournament play, broadly similar but somewhat reduced in scope and power to facilitate an even playing field for tournaments (UK-based tournaments anyway)
15. Can you mention the most important EPIC ARMAGEDDON links or ressources?you are already here

it takes a while to find your way around, but between this place and the SG section on GW's website you're pretty well covered
oh and welcome
