1: there were some crashing issues with scenarios yesterday, so they were taken offline to be fixed.
2: my secondary PC's run WAR with absolutely no lag running 2gig ram, 2gig dualcore CPU, 8600GT's (with low settings). try turning the settings down gradually and disabling useless effects such as grass and shadows.
3: you can gain renown participating in RvR areas, PQ's, etc, without directly participating in PvP.

as a little side note.. if PvE isnt your thing.. you can actually level quite quickly purely via scenarios (as long as youre on a decent population server with frequent scenarios running). i leveled 1-11 on my team with two bright wizards and two runepriests in a few hours two days ago. stand next to your scenario quest giver and just keep accepting/completing the quest. i was averaging around 8,000 experience per 10 minute scenario, plus another 700 for completing the quest. thats nearly 900 experience per minute not even including any experience you get from kills during the scenario (50-100xp per kill).

ontop of that, i easily capped out my renown each level, before i attained the next level. i was RR10 already when i hit level 11.. plus the gold is quite decent from scenarios. over 1 silver per kill per group member from equal level PvP kills, plus another silver and a bit each from completing the quest. when you hit 10 you can buy some awesome PvP gear from your faction keeps.

all in all, i was surprised that this game actually seems to live up to its promise of viable PvP leveling.