if you plan on doing endgame with tranform pots, strength is the way to go. str/PAx6 or str/PAx5+dex/PA.
anything less and dex is preferred.
as far as tp, all your masteries should be maxed, common sense. if you going strength build, don't need anything in swiftness, but if dex, it's quite useful. target area is a nice crit boost. blood arrow NEEDS to be maxed. most of the other stuff is personal preference/combo dependent/situation dependent.
for example, as s/r, reflected shot isn't worth it to put much tp into(or even really using much for that matter) if you ONLY want to do single target, with no adds, yet becomes amazing as soon as you introduce some other targets.
if you are going to be switching between s/r, s/w, and s/wdn quite alot, start putting TP into the skills that are used by the majority of the combos, like combo shot, piercing, etc, before you start putting tp into elites or skills only used by one combo, and even then, prioritize support skills/buffs first.
if you are seriously tp-starved, it's better to have your buffs and such high, as they provide a global damage increase, whereas one skill is only one skill, and with the scout damage formula, depending on your damage/gear and skill%, leveling it can have disproportionatly small effects for the cost.
for example, leveling a ranged weapon skill from 0 to 90 can result in as little as +50% damage with minimal buffs(might not even be the smallest increase, i stopped looking after hitting 50%). that is a single skill, which will most likely be a fraction of your total output damage. much better to use that same tp to get multiple other skills in your rotation a tad higher, or better yet, increase a buff or support skill.
all about RoI.