As far as I know, I don't think there have been any human tests on 2C-TFM. I think its safe to say is probobly not for the average tourist.
Regarding replacing the benzene ring, there are countless examples of 5-membered ring aryl ethylamines, with a huge range of biological activities. The geometry is completely different, and so each family of aryl ethylamine essentially has its own set of QSAR's.
To put it another way, consider this: phenethylamines are ethylamines with a 6-memeberd aromatic ring structure, tryptamines are ethylamines with a 7-memeberd aromatic ring structure. The two classes of compounds contain thousands of enormously active biological compounds, but little more than that essential structure -- aromatic ring, -ethyl, -amine -- really connects them.
Its not an entirely bad idea. Don't forget, 6-membered heterocyclic rings (like pyridine) are still a possibility, as are many others. With the right chemist (and the right budget), an entire library of "iKAL's" could be written. With the addition of a heteroatom, the ethylaminee chain could be added in multiple places, adding the possibility for countless more arylethylamines! Here are a few "new" books that came to mind:
BiKAL: benzofuranylethylamines I have known and loved
FiKAL: furanylethylamines i Have Known and Loved (you have to
love the sound of that acronym
)
NiKAL: napthylethylamines i Have Known and Loved
PyiKAL: Pyridinylethylamines i Have Known and Loved
ThFiKAL: Thiofuranylfuranylethylamines i Have Known and Loved ("ThFi-" is the sound you make when you smell these compounds - ick..)