Something that can be fun is to share a voice channel with your guild or RP buddies to leave your hands free. Oddly, if the people on the channel are inclined, things may very well slip into character and banter will ensue during battles, charges and so on. Not to mention it's just fun to be in a tense situation with people you know and trust - my sister and I so love zerging together because statements of "Oh holy....." are well understood and "LOOK TO YOUR LEFT!" , "Get out of there!" etc make it feel quite real. And yes we do this in character and it's often hilariously funny - her charr likes the taste of human and dearly wishes for carnage to ensue so he can enjoy his favorite forbidden delicacy - never trust Kazimir Foulpaw if you see him coming to 'rez' you.
Small teams in wvw are a great strategy - a 5 person party can easily take an unguarded camp and I have, in fact, seen a charr warband guild (shade warband I believe) in character and taking camps. If you can get the camp taking down to a science you can avoid alerting the enemy before it flips (I believe 30 seconds).
I would be really careful of RP walking in wvw though. I've died a couple times while doing it just because in my excitement to engage the enemy I can easily keep myself locked up in it for longer than I shoulld! I do RP walk dolyaks quite a bit though and I have talked with various people about whatever while on caravan duty - people are very friendly in general and it's rare to be completely ignored though IC conversation might not always happen.
Another thing too - it's not impossible to interact with the enemy - the standard emotes work between servers. I've managed to work my way around an enemy held map to get skills and view points entirely by bowing, cowering, shrugging and waving. You will get killed but also you will meet people who will tail you and wave and hop up and down and be quite delightful. I recommend trying it just for experience - I more or less made friends with an FA mesmer last night and we just cat and moused around the borderland but in the end we were waving and hopping like fools when we saw each other - sure he tried to kill me and I tried to kill him but it was a stalemate as far as skill and damage and honestly he seemed unconcerned at my dolyak slaughtering other than tossing me around a bit and knowing damn well I'd get the kill anyhow I like to think he was having a good laugh at this kooky TC person running around all alone.