While not exactly an answer to your question....
In order to have a full set of "rogueskills", all you need is one level of Rogue/Artificer/Dark Hunter and enough INT to invest in search/spot/disable/open lock. I often lead off with a level of rogue at level 1 and take a second level of rogue at 20 to pump out the UMD that I have intentionally let slide just enough to max it and my rogue skills at level 20.
If you want evasion* (which is nice, but not something I typically aim for, my current trapper is 2/18 rogue/fighter in heavy armor, so evasion capable, but not something I build towards using) all you need is a second level of rogue/monk or 9 levels of non-DarkHunter Ranger.
Investing heavily into INT for the INT dependent rogue skills (Search/Disable, the only two skills needed for the trapping side of the rogue skillset) makes going into either Wizard/Alchemist for the spell casting synergy or Harper Agent or Alchemist (Battalion Brew) for the INT to-hit/damage a wise move.
Or even relying on Artificer's Insightful Damage spell in conjunction with Harper Agent's INT to-hit to conserve action points on the proper build is even a viable thing.
This opens up a wide range of potential builds that are quite viable without shoe-horning you into one particular thing.
Just a couple class combos:
2/18 rogue/wizard
2/18 rogue/fighter (Harper Agent, heavily invested in the THF and Heavy Armor feat chains)
2/18 rogue/alchemist (Inquisitive, evasion early with Liquid Luck, swapped out later for Heighten with second level of rogue at 20)
2/18 monk/artificer
6/14 monk/rogue
Heck, to be honest, you can make FUN (but arguably less than the purists needs for an OPTIMAL) build by mixing up some wierd stuff. And sometimes get something that's both.
You only need 3 levels of Bard and 11 AP to get Swashbuckling with an orb/runearm/buckler (with both SWF & ShieldMastery feats). Two extra AP and you can take Different Tack: Two Steps Ahead to make INT-to-Damage a thing. 4 levels of basic Bard (non-stormsinger) gets you some other build related tasties worth considering at 21-26 total AP expenditure.
So....
3/2/15 Bard/Monk/Artificer
and while I haven't tried it or even thought about it before now....
3/2/15 Bard/Rogue/Warlock(Enlightened Spirit) might be super fun.
At any rate, my point is...if you want Rogue-skills (or just trap skills), the basic idea is you need at least 1 level in a class that grants access to them, and enough skill points per level to keep them invested in (at potentially cross-class point expenditures).
After that, the rest gets....fun....INT to hit/damage or as a spell casting stat is great synergy, but not required. Especially once you consider skill boosting equipment/spells/tomes, etc. Heck, you can even make a passable Barbarian into a trapper with a 2 level rogue splash. Giving up the capstone is only really a huge sacrifice if you plan on LIVING on the build. Otherwise, good/fun viable builds don't have to be optimal-on-paper.
I'm really starting to digress here, but I've been thinking recently.....
Barbarian 4, 23AP in Ravager
Fighter 4, 23AP in Stalwart Defender
Artificer 12, 31 pts in Renegade Mastermaker
Harper Agent, 3 pts
No evasion, and I'd have to look into it deeper to see if/where it breaks down, but could be fun. It won't be soon, though and I already have variations in mind to try on it.....:
:
*Footnote: Keep in mind that evasion only works if you MAKE your reflex save to begin with. Builds with lower reflex saves make Evasion increasingly ::meh::. I'm not saying you should ignore your reflex saves....just pointing out the relationship. And builds that don't have stellar reflex saves DO exist. And some of them are quite viable as well.
**Edited for spelling.