I would wait a while, there are some new stocks coming where barrel channel gap will not be a problem anymore. Including an incredible wood-type one. The moisture problem is inherent in wooden stocks, some are worse than others. A friend who bought an Icon sanded and sealed his barrel channel a smidge to open up it up, then centered it and it has stayed perfect for some time now. If mine appear to move I check that there is no contact with the barrel, if none I just shoot it. Have noticed it with the .30TC but not enough to worry about, unless a guy is quite particular.
The bedding can be tightened-up with a skimbed of Marinetex or something similar, but I have never heard of anyone doing that yet. When the barrels get heavier this might become a reality.