What did you lube the brake pistons with? Get some brake cleaner spray and clean them out. They shouldn't be lubed at all. How disk brakes work: When you pull the brake lever this forces brake fluid down into the calipers which force the pistons out against the disk. We all got that part, here's the trickier stuff. to move the pistons out, the Orings that seal the pistons roll with the pistons' movement. Once you relieve the pressure on the lever the master cylinder backs up pulling the piston back with its vacuum. The rolled up orings helps pull the piston back, too. As the pads wear, the oring should slip enough to keep the shrinking pads at the proper clearance. Sometimes, you will notice you have to pull the lever back farther than usual. That's because the oring is getting some dirt behind it and won't move out as it should. To get the lever travel back to the point that it was originally, at a stoplight, pull the lever back fairly hard and hold for several seconds. This will force the orings to move. You may have to repeat this a few times to get all the travel back but the lever should get back to very near where it started originally. If the pads start rubbing the disk the area around the pistons is getting too dirty to let the orings do their job. Pull the pads and Push the pistons back into the calipers and clean out the slots, then put the pads back in and do the squeeze play again.
Do not lube the pistons and calipers. there is a chance of getting the lube on the pads, the lube will attract more dirt and most of all, it will let the orings slide and not be able to pull the pads back as they should.
As for losing part of you speedo drive by leaving the cable out, some of them have a little adapter in them to engage the cable. Make sure either that is out or won't come out. I would suggest, preferably a screw on cap for the cable hole or at least taping it over to keep dirt out.
Bare