Unless the drug
is dissolved into a solvent that is used to deliver the drug through transdermal pathways, such as DSMO (Dimethyl sulfoxide), it is highly unlikely that you are getting "extremely high" from touching the said substance directly.
You also just said the "dosage for a good oral effect [sic] is only .1g-.2g of powder." This statement tells me that the drug, being active at 100mg or 200mg, is obviously going to be less likely to be bioavailable in the realms of transdermal delivery
due to such a dose being far too high for a drug of that classic category. Typically, it takes a drug dosed in the micrograms before skin direct absorption becomes a reality.
1.) I think you have a placebo effect going.
2.) Buy a Marquis reagent
3.) No, there aren't any drugs
directly in powder form that can go through your skin callouses to get you high. I have had no drugs, in my experience, make me high unless I directly inserted them into a place where they could, in fact, get me high, or they were in solvents that could actually penetrate the outer heavy layer of skin.
4.) None of us can identify a drug online. Get a kit.
This is really a matter of being logical. You will only know by testing it with reagents.