considering the potential for flat or negative returns in the near future from BRK, makes me consider selling some and doing something else with the money. But, I also am trying to be better about just holding the damn stock.

Holding the stock is absolutely fine, as long as you're cool with expecting some fairly modest returns for a while. Selling some stock to try to find a better opportunity at some point is also fine, provided you're cool with the observation that it's hard to buy things when panic sets in, and in any case nobody knows how long the wait might be.

Personally, the main reason I go on about such things (other than my geeky nature) is to make sure the minimum number of people opt for an alternative that isn't fine: simply expecting that the price will keep going up without any concern about valuations rising towards infinity.

This isn't generally a big problem with Berkshire holders, but it's distressingly common in other areas of the market. It's just nice to have your eyes open. If you expect your tree to grow to the moon, you'll be disappointed.

Jim