UA T2 -> VN T4 Transfer?
I'm looking at a UA flight from SFO that would be scheduled to arrive in SIN at 6:45pm in T2. UA has me continuing 2 hours later on a VN flight out of T4 to SGN. VN flight is not a codeshare, but booked through UA.
1) I assume my bags would check through?
2) I doubt I'd be given a real boarding pass in SFO, does VN have a transfer desk at T2 to get a real boarding pass?
3) The bus transfer from T2 is landside. Is there a way to take the airtrain to T1 or T3 and then take an airside bus to T4, all in that 2 hour window? I may have visa issues if I have to pass through immigration to transfer.