as long as you're using a chiller to bring the temp down pretty rapidly, there's no real reason to adjust. there's definitely no reason to adjust your dry hop addition.
there's a school of thought that postulates that aromatic compounds increase proportionally with alpha acids, but i'm not...
add the juice in primary. they yeast will have quite a bit more sugar to deal with when you add it, so you want a decent population left to ferment it down. If active fermentation has subsided, you'll be getting the benefits of adding to secondary anyway.
Could be an infection, but could also just be age highlighting some other flaw due to process. A hefe has a lot of "freshness" that can hide flaws for a while.
recipe/process details?
you probably would have had the same problems with beer - brass or stainless would work great (stainless always has a narrow advantage). Plated fittings can give you trouble, since it doesn't take much to breach the plating somewhere, and then it's all over.
for my money, I went with the BarleyCrusher. Very happy with it.
I wouldn't bother with those 'upgrades' unless you foresee some major abuse in your brewhouse.
Can't recommend the BC enough. I only wish I could make a commission recommending it :)
sounds like you need to pick up some oak chips! I have had some great barrel aged beers, but overall, I'm not as sold-out as you seem to be. I still enjoy the more traditional treatments just fine :)
do you use big, healthy yeast starters? this will fix SO many problems. if using dry yeast, be sure to rehydrate properly. poor yeast health can lead to either uncarbed bottles or excessive FG which turns into overcarbed bottles in the long run.
I transplanted mine 1100 miles by cutting them off, digging up as much of the roots as possible, and bagging them. replanted by burying the spread-out root structure under a small amount of earth. worked fine.