Zsultan,
On the battery is it 15A or 15C??? Big difference!!! 15C I'd say your good (measn your getting more then 30A continuous) but 15A won't cut your power needs and you'll probably damage the battery!!! And why do you only have two servos on swash? lol. I assume you ment three, hs-55s are a little weak but there's enough combos out there with them that I guess they'll get you in the air, I'd at least get hs-56s. Gy401, EXCELLENT!!! I don't know the servo your using but it's digital so it can't be horrible and will probably help realize the GY401's full potential.