The difference between a wet lay up and bagging it is that when you bag it you apply a constant suction to plastic surrounding the glass/part. This helps to ensure a tight bond and proper penetration of the glass by the resin.
For taking off the bottom, there are some of the push pins and I believe a couple torx bit screws. Should be pretty easy.
If there is enough material, 3 layers is typically prefered. The first layer, one laid 90° to it,.and then one final laid at 45°. In this type of component I wouldn't be overly concerned. I did a wet lay up with two layers, one at 45°.
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