RE: go board
There's probably no "easy way" to repair bubbles in the EVA.
About the best solution is to take a needle and basically "pop" them.
The are caused by small pockets of air that were trapped under the EVA when the board was made.
Over time, and especially if the board lays out in the hot sun with the EVA deck up, these little pockets of air expand and create a bubble when the glue that attaches the EVA to the underlying skin of the board loosens enough so that the EVA material pulls away from the skin of the board.
You could open them up and re glue the EVA, but that normally ends up looking ugly.
If you just "pop" them so that the pressure can no longer build up between the skin of the board and the rubber EVA deck material, they usually pull back down, and since there no way for the pressure to build they stay down.
If you have larger areas, you might want to get a syringe of some sort and inject a little contact cement into the cavity and then weight the area with sand bags until the contact cement "rebonds" the EVA to the deck material under it.
Be sure to check that the deck is solid under the "bubbles".
If not, you have a different problem and will need to open the EVA to inspect for damage underneath.
If you are careful when you cut the EVA, and very carefull when regluing it into place you can do a pretty nice looking job.
Hope this helps,