[RPG] How to build a rogue unchained to be able to fight with 2 blade boots and 2 daggers

Based on the alternative class features thread, here are your options:

Rogue

• Antiquarian – +Wis to Appraise for divine items, can attempt to identify divine items
• Changeling Rogue – 10+Int skills/level, one Knowledge skill of choice as class skill, gain Social Intuition (several special features with social skills)
• Drow Rogue – Poison Use
• Mimic – Disguise self

Scout (none)

So only one that you missed, but it’s a really good one. Anyway, rogue/scout seems like a kind of poor multiclass to me; they overlap on a lot of things and their primary differences don’t synergize very well (rogue wants to flank, scout wants to move).

With the build I'm going for the Drow Rogue looks the most viable but really poison use appears to be more trouble than it's worth (especially with the cost of decent poisons...)

Poison Use is almost useless; if you want to specialize in poison, you really want the Master of Poisons feat from Drow of the Underdark, which gives you Poison Use and the ability to poison a weapon as a Swift action.

That said, poisons can be worthwhile, and better you can make decent use of poisons without investing heavily in them. Having Poison Use rather than Master of Poisons is mediocre, but Craft (poisonmaking) can generate substantial savings on poisons (prices as low as ⅙ the base cost). Tossing a few points in Craft (poisonmaking), carefully selecting cost-effective poisons, and having Poison Use can give you a fairly potent low-level option.

For more about making the most of poison, check out Arsenic and Old Lace.

A long-running Pathfinder campaign in which I was involved that ended when characters were level 14 included—at one point or another—a half-orc inquisitor, a human barbarian, a human cleric, and a vanara druid. The campaign had the PCs as police detectives in the Magic: The Gatering setting Innistrad. Adventures involved a great deal of investigation and mundane legwork plus plenty of we've-discovered-your-evil-plot-so-it's-over! sort-of reveals in addition to beating the crap out of a lot of evil outsiders and undead.

This list is in no way comprehensive and instead limited to items I've seen used in play in an 18-month-long campaign that had a significant combat encounter only about every other session. I've further limited the list to only the items a fighter could employ.

• The half-orc inquisitor wore the bracers of the falcon's aim (4,000 gp; 1 lb.) that grants a +3 competence bonus on Perception skill checks in addition to other effects; the jingasa of the fortunate soldier (5,000 gp; 3 lbs.) which, while a combat item, I'd be remiss were I not to recommend; and the mushroom vest (500 gp; 3 lbs.) that lets the wearer treat falls as 20 ft. shorter, which, admittedly, isn't the boots of the cat (1,000 gp; 1 lb.), but the boots slot is premium real estate in Pathfinder. When needed, he'd doff the vest and don a robe of infinite twine (1,000 gp; 1 lb.). I'm pretty sure he also wore the heavyload belt (2,000 gp; 3 lbs.) and the muleback cords (1,000 gp; 0.25 lb.) so that the weight he could lift, drag, or push was measured in tons. At later levels, he discovered the gloves of reconnaissance (2,000 gp; 0 lbs.) and cried a little, regretting he'd not been wearing them all along, then never took them off.
• The human barbarian with the drunken rager archetype had several utility magic items so that, despite not casting spells, he could feel useful during investigative portions of the session. These included the cloak of the hedge wizard (transmutation) (2,500 gp; 1 lb.) that cost 50% more because it was combined with his cloak of resistance +3 (4,500 gp; 1 lb.), a wayfinder (500 gp; 0 lbs.) with an ioun stone (clear spindle) (4,000 gp; 0 lbs.) so that together they resonated with an immunity to mental control as per the spell protection from evil, the ioun stone (eastern star) (4,000 gp; 0 lbs.) so as to be able to read and understand all languages, the noble's vigilant pillbox (3,600 gp; 0 lbs.) because of its detection abilities, the ring of the sophisticate (11,000 gp; 0 lbs.) so he could find a bar anywhere, and, later in the game, the expensive drinking horn of bottomless valor (24,000 gp; 2 lbs.) that was useful also as a source of endless booze so as to freely liquor up suspects and witnesses to get them to talk.¹
• The human cleric's player's first big purchase for any of his characters is almost always the hat of disguise (1,800 gp; 0 lbs.), which is probably near the top of almost anybody's Versatile Magic Items list. Looking back, I would suggest now that he buy first—and later pay the extra 50% to combine the hat with—a cap of human guise (800 gp; 0 lbs.) because it's cool, too.
• The vanara druid's elephant animal companion wore a belt of the weasel (10,000 gp; 1 lb.) so that the elephant could more easily enter people's homes during investigations. (Shockingly, folks were still uncomfortable having an elephant in their homes.) However, the party soon realized the belt's utility value, and the belt ended up as often on a party member as the elephant. If the belt seems overpriced, then reread the universal monster ability compression that the belt also grants: it's awesome ("You can squeeze through a space how little exactly?"). The vanara druid herself wore a ring of eloquence (3,500 gp; 0 lbs.) but custom made so as to include, instead of its typical languages, the four elemental languages so that she could communicate with her summoned allies.

In retrospect, we weren't using several items that we probably should've been using. In addition to several ioun stones (cracked orange prism) (1,000 gp; 0 lbs.) each for the casters because more 0-level spells is incredible, I'd want now, for instance, the headband of intuition (7,000 gp; 1 lb.), at least one insistent doorknocker² (5,000 gp; 2 lbs.), and the treasure hunter's goggles (6,400 gp; 0 lbs.).

¹ The drinking horn supplemented his low-level purchase, the tengu drinking jug (1,000 gp; 2 lbs.). He'd tired of the one gallon of sake or plum liquor ("Tastes like pruno") the jug could create each day, even though it was sort of free.
² Two doorknockers are better so that you can make a door then make another door on the other side to recover the first doorknocker, but even just one's great for a case of the lookarounds.