Its armor this time. Now does an Armor?s Quickness Penalty reduce Qu bonus for everything (qu-related) or just DB?
Just for DB. For skills (Moving Maneuvers), you use the Maneuver Penalty as adjusted by the appropriate armor skill.
Anywhere I can find AT for scalemail and and banded (Lorica segmentata)?
That is one of the drawbacks with the current RMFRP armor rules, each AT represents a specific suit of armor, so it is very hard to add new types of armor or any sort of "Armor by the Piece" rules.
IIRC, there aren't any RMFRP supplements that might have that information.
However, the RMC book, Combat Companion, does take into account different styles of armor and so forth, and it does include Plate Scale (and Leather Scale as armor options. And while the Combat Companion can be used with RMFRP, to be able to do all this with armor, it had to completely change the armor system to do so.