If you have an 11-30 with a 52-42-30 crank, your drivetrain's total capacity needs are (52 - 30) + (30 - 11) = 41. So your stock RD, being able to take up only 35 teeths' worth of that, is going to have to let your chain hang limp in some of the gear combinations when you're using the small front chainring. If that's a problem, use a longer-cage rear derailleur such as the Acera mentioned earlier.
and speaking about gears being funky when i change im just wondering when i tune my bike it changes gears fine but when im actually pedaling on it, it shifts totally different is that common and do i just need to get better at tuning or is there a bigger issue (ie laggy gear change, or skipping, but not when im tuning)
No offense, but if anyone wants good answers, it helps to use some punctuation so we can understand the questions without our brains essploding
Yes, sometimes shifting behaves a little differently in real life than on the repair stand.