I think slight accents should implemented. I mean, shouldn't rp be realistic? When a german speaks english to me most of them do have that epic accent. Same for Russians, Dutchies etc.
Accents are fun to rp as long as they don't drown the meaning of what you are saying. But people whining about rheinlanders using 'zis' as opposed to 'this', 'haf' as opposed to 'have' etc should just use their brain for 2 seconds longer. Personally, I think it looks weird when SCRA, RM and Kusarians all speak fluent, accentless english.
Also, mix in the occasional foreign word, as long as its easy to figure out what it means via the context of the line.
as in 'Blow zat shiffe up'.
Is it that hard to realise it means 'blow that ship up'?