Hi shatarj, welcome to the forum. You want to get your overall util, as well as individual util, under 10%. Then, you want to have less than half of all open accounts show a balance.
For the collections, you want to ensure that you know what your SOL is for your state and when was the DOFD/DOLA. (If you can work with the OC, then it's better for you). If you are near SOL, you want to let that dog sleep. If not near SOL, then you want to DV the CAs. If a couple of tries at DV fails, then you want to do PFD. You don't want to pay off a collection without something in it for you. If you do, then you will get the distinction of having a "new" collection (score-wise anyway) on your report called a paid collection. The reason being is that you have brought the report date closer.
When was your 30 day late?