When I did my testing I tried working with larger profit targets however the 2:1 RR was what worked out the best for what I was doing.
I am not saying I have done a complete and thoroughly exhausted back testing however what I am doing right now seems to work.
To your specific questions then no, I have not considered round numbers as profit targets as I do not see minor round numbers having any significant influence and major round numbers are to far in between to make any sense with this kind of strategy.
I am not trying to take out large pieces of the moves but instead small consistent pips.
I did some retesting and I think I will try to stick to trading GBPUSD exclusively for now using the same strategy but with a 15 pip stop loss and 100 pip profit target. Overall returns back testing much more impressive.
Going forward I will stick to trading the pairs I have back tested that show good results instead of just any currency pair that looks to have a good setup.