I pre-wet my fabrics in hot water and then dry in the dryer. The only time I tried to starch before cutting, I messed up both my iron and my ironing board cover. I have decided that I prefer to work with 'raw' fabric. If it is going to mess up then do it before I have put in the time, money and effort into a quilt top.
Pressing seams. Having started out as a sewer of clothing, I had a lot to relearn. Pressing means to set the iron down and not move it and then lift it up and repeat. Steam is an option and can be used in many ways. So can a trusty spray bottle. (Ever had a block that seemed to stretch or skew?? Dampen it, lay it on the ironing board, choose the best side, pin it down, and then measure off that, stretching or easing as necessary and pinning a lot. Then just let it dry. You will be surprised with the result.