Scout/Ranger

[okpokalypse]

So, Tactile Trapsmith lets you use INT as a dump stat. This is bad because?

You still need Int for Skills. There's no getting around it. You're way too dependant on a lot of skills having high ranks to ignore it.

Specialization is good. I don't care about skills, I care about the skills that matter.

As a Scout / Ranger, the skills that matter are:
Listen, Spot, Disable Device, Search, Hide, Move Silently, Survival and Tumble. Those should always be at max ranks, and if you've got a negative Int modifier, you can't accomplish that.

In addition you'd like want to put ranks into other skills as well:
Balance, Climb, Jump, Knowledge (Nature) and Use Rope should be used just for the usefulness and synergies. You might also want Escape Artist, Knowledge (Dungeoneering) and Knowledge (Geography) as well.

My Elven Scout/Ranger has a 14 Int, and I still need more skill points to flush out everything as I'd like at L9.

Really, the build OP presented - Scout 4/Ranger X is in fact a combat build and not a skill monkey, and Tactile Trapsmith allows the build to apply its key combat ability - DEX - to the one skill it uses. Again, reduce MAD, dump INT for combat stats, increase synergy for when you up DEX. With one feat you can make the build quite good at the single skill most parties expect out of their skill monkey, while keeping combat stats high and not actually becoming a skill monkey and sucking at combat, as you say.

If you're talking about not being a skill monkey, and just going with literally 4 primary skills (Disable Device, Search, Survival, Tumble) - then it could well be worth it. But I'd still use some other feats that I feel more efficient...

Hamstring (Sacrifice 2d6 Skirmish to Reduce Enemy Movement by 50%)
Hear the Unseen (Locate Enemy Via Sound)
Telling Blow (Add in Skirmish Damage with Criticals)

Telling blow is especially nice if you are allowed to take a 2-level Dip into a 3.0 PrC (Deepwood Sniper) to get your multiplier up to X4 and get automatic Keen Arrows (No need to Improved Crit your Bow). Not to mention Concealment Reduction and a Range Increase as well.

With an Energy Burst Weapon & Telling Blow, at L12 Scout/Ranger/Deepwood Sniper Combo is critting on a 19-20, and doing Weapon Damage x4, 5d6 Skirmish Damage x4 and d6 + 3d10 Energy Damage.

Assuming a +2 Longbow w/ Energy Burst, that's an average damage of 116 on a Crit. That ain't too shabby.

It's also nice for melee Scout/Rangers who don't go DwS because a Keen'd Rapier's got that 15-20/x2 Crit Range. 30% Chance of your hit doing 10d6 Damage by L9 - so long as you've got the Improved Skirmish feat boosting it by +2d6.