A religion need not involve a diety, dieties or the 'supernatural,' whatever that may be. "Church" may not accurately define the institutiton that is Scientology but let's go by your checklist here....
Church Defined - IRS Church Definition
1. Distinct legal existence. - Gee, that's not vague. But we'll give 'em a check.
2. Recognized creed and form of worship. - 'Recognized' by whom? Regardless, Scientology has a creed. 'Worship' is slippery too, but we'll again let it slide...
3. Definite and distinct ecclesiastical government. - 'Ecclesiatical?' Way to get circular, IRS! There is nevertheless a hierarchy and chain of command in Scientology
4. Formal code of doctrine and discipline. - Our first clear-cut criteria (mostly)...Scientology passes, here.
5
. Distinct religious history. - 'Religious' is left undefined. And even 5 minutes is a history....yet again, Scientology would pass
6. Membership not associated with any other church or denomination. - Given how "other Churches and denominations" shun or disassociate themselves from Scientologists, here's another "check"
7. Organization of ordained ministers. - 'Ordained' by whom...the same that must 'recognize' their creed or worship? Still, Scientologists have appointed leaders of worship and authority
8. Ordained ministers selected after completing prescribed courses of studies. - Almost a redundancy; checkerooney.
9. Literature of its own. - Dreadfully; check-o
10. Established places of worship. - Yessir
11. Regular congregations. - How 'regular' is 'regular?' But, yeah, again.
12. Regular religious services. - As distinct from their 'regular congregations?' If you say so, Mr. Taxman; yet another check for Scientology (Ps. what're 'religious services?' reminds me of the old joke about priests and prostitutes....)
13. Sunday schools for religious instruction of the young. - Now if that doesn't show a bit of bias.....Sunday, Monday, anyday - Scientology is out to (*ahem*) 'instruct' their young and the next generation
14. Schools for preparation of its ministers. - Do they need to be 'recognized,' too? This goes along with #8; yes.
Well, the IRS is obviously a reliable authority on the matter, for sure...
I guess my point is, church and cult are not as distinct as their common usage might suggest, and neither are excluded from being a 'cancer.'