Everything works just fine until I run the engine for a bit and the fuse for the tail/brake lights and instrument cluster (10A) blows out. Could this be due to the extra bulbs (I followed the recommendations to the word) or is it from a short someplace? It only started happening when it got rainy, even though I haven't ridden it or gotten anything wet.
what type of bulbs did you install into the side pods?
If you used 1157's, I think that may be a little too much. I would get some red 1157 LED's (off of ebay) asap. LED's require less power than halogen bulbs.
but first, you should double-check your wiring. Make sure nothing's touching the frame and make sure none of the wires are touching. Those are two definite reasons that fuses would be blowing consistently
Of course, if you didn't solder on a ground wire then that could also be a reason for blowing fuses.