i find this part strange. i don't see why someone would need to enter a country to get to a check-in counter. all of those services are available air-side at every airport i've ever been to. if the pax has an onward ticket, then there shouldn't be a problem. they should be able to prove that with a copy of the booking reference and details.

having two separate tickets, no baggage, and on an award ticket bought by someone else? now those things will definitely raise red flags. in my opinion, and that's just my risk-averse opinion, not fact, you are asking for problems. please do tell us how it went should you decide to go ahead with this.