Forgive my posting these questions here...I tried on another forum, but got no answers and I need to decide on this trip very soon. I've also done some searching at FT and at visa processing sites, but remain somewhat confused. So perhaps I'll have better luck here:

1. In mid-March I may overnight in DEL flying between San Francisco and Kabul. If arriving on AA, the overnight would be on the outbound for about 15 hours; if on BA, the overnight would be on the return for about 8 or 12 hours. Air India between DEL and KBL. FWIW, the tickets would be in J. Is the airport transit hotel open yet? If so, would I need to clear immigration and security in transiting from AA or BA to AI?
2. If I do need to clear immigration and security, am I correct in assuming that I would need a visa (I am a US citizen, not of Indian origin)? And if so, is there a transit visa or would I need a regular tourist (or other) visa?
3. If the airport transit hotel is not open yet, what are the best nearby options for overnighting?
4. There is also a chance that I will need to attend a conference in New Delhi in late February. If I correctly understand the rules, it is possible to get a multiple entry visa, but one cannot re-enter the country within two months of leaving it. So what is the best process to follow in the event that I need to visit the country in late February and then pass through again in March.
5. If because of the multiple entry problem I might want or need to remain within the airport and the transit hotel there is not yet open, are there any lounges or other options for grabbing a shower and sleeping through the night there?

FWIW, instead of passing through DEL in March I could possible route through Dubai to get to Kabul. But for various mundane (though not on FT!) reasons--mileage accrual, upgrade possibilities, price--I might prefer DEL if possible.

Thanks for any advice and info!