Q 127: In the description for the Devotion feats in CC, it doesn't state when you have to trade in the Domain for the Devotion feat.... If you were a human and took Able Learner and grabbed a rank in each of the Knowledges, could you then swap out the Domain for the Devotion feat, and be able to max out all of them?
A 127: Relevant rules: Complete Champion page 53 for Clerics and Domain Feats; Player's Handbook page 58 for Level Advancement; wherever it says that you cannot take an HD feat and start a PrC for which it is a prerequisite at the same level.
My reading is that swapping a domain for the relevant domain feat can be done whenever you level. Thematically it makes sense - as your Cleric's faith matures, they focus on worshiping their deity/ideal in a particular way at the expense of another connection. This also makes sense from a marketing perspective, as WotC seems to like to give options to existing characters without requiring you to start a new campaign or retcon an existing one whenever you shell out for a new splatbook. I could also see treating as an Alternative Class Feature, though, which would require that you select the domain or the feat the moment you gain access.
Select domain -> spend skill points -> trade for domain feat all at the same level is pretty cheesy, as you are getting two benefits for one feature.
The Knowledge domain puts all knowledges on your skill list, and you do not need to buy any ranks for the improved cap to remain in place. Factotum 1 + Able Learner = all skills cost one rank and have a cap of HD+3 forever.
Q132:
Does the rules differentiate between creatures of different size when I attempt to shoot into a melee combat? I get shooting one of two medium-sized combatants will be harder, but what if I want to shoot a colossal dragon that are trying to stop a tiny housecat ect.?
A132: Rules Compendium page 16 sez that as long as at least part of the target creature is at least 10' away from your ally, you do not incur the -4 for shooting into melee. You can aim for the part of the dragon that is not currently munching on Felix.