I start sewing on a little scrap of fabric, then, without cutting the thread, maybe sewing without any fabric under the needle, start sewing my block. At the end of the seam I do the reverse, sew right off the block onto a scrap.
This method saves thread in the long run and helps avoid the occasions where thread "balls up" under the fabric and potentialy snags the fabric under the needle. This will help with problem # 2 above. I wonder if your tension needs adjusting so that the threads don't pull so tight.
Question # 3 leads me to think that you may have too much or too little pressure on your presser foot. Try adjusting it to the mid point on a scrap of fabric and see if that's any better.
A bobbin should move freely in the bobbin case, too much and it will drag. Too little and you will drive yourself crazy refilling the bobbin every 5 minutes.
Best advice for a newbie is find a local quilt shop . There's always help available there. If they can't help, they usually know where to send you. Welcome to our addiction! We love newbies.