1. There is no perfect builds because there are so many different play styles. A Rogue can use a blender spec (Blades, Razor, Traps, Aimed), or a Max DMG Spec (Bow, Pierce, Nox, Aimed) or anything in between. It is mostly dependent on what your attack methodology is and whether you want to be reliant on a party or are willing to be in more of a support role.

2. Architect offers better armor and better, general all-around stats. Hellish of Potency offers the best pure DMG stat, but sacrifices A LOT of armor.

3. I would say both. Blades are suitable for mobs, bows are better for bosses. Blades have superior DPS and can attack up to 3 mobs at a time; however, bows have substantially better DMG (meaning increase DMG on skills as well) but are single target, therefore best suited for bosses. Keep in mind that Architect Quills have a terrific PROC with +50% Crit bonus, so generally I use blades. At lower levels, Mountain Teeth also offer a good PROC, but Devourer Bows offer substantially better DMG, so it is based upon whether you are armored enough to get into melee range, or prefer to kite to avoid most of the damage.