Did 1L year at GGU, top 7%
Transferred to Santa Clara University, top 12%
Only took one tax class, Federal Income Taxation, B+.
No tax experience.
Any chance of getting into Georgetown Tax LLM?

P.S. please spare me lectures on how "low-tier" my schools are.

Don't need anyone to tell you it isn't impossible, just improbable. GT as you know is highly selective. Having said that, I'd suggest applying anyway. What have you got to lose? At best you get in, at worst you just make them look more selective.