You absolutely cannot bypass the bobbin holder; it supplies the tension for the bottom thread.
I've just started sewing with Bottom Line thread from Superior Threads. I'm amazed at how much will go on the bobbin, and I'm using it for the top thread too. A spool seems to last forever, and the thread takes up so little space that the seams iron much crisper than with bulkier threads. I usually wind about 10 bobbins at a time, but when I started with this thread I wasn't sure that I would like it, so I wound only one bobbin. Now I'm going to go buy more Bottom Line and use it everywhere.