Wickham is young and already proven(to an extent) in this league. I would be shocked if, when the pressure is on, Bamford gets the continual nod over him. Hell even in Kane's situation it only really turned out the way it did because Adebayor COMPLETELY went off pace and Soldado never fit in this league.
Lol you are giving a lot of what-if scenarios mate. I can only speak on what I know, and I know Remy is good enough to run the show for a few weeks. I also know our defense and midfield is what our titles are won on, and I don't see that out if Costa is out or have a slight dip in form.
Injury prone or not he is still too good to be second choice to any other striker on earth. Remy and falcao could easily handle 3 games a week between them. In fact, Remy could probably handle more games than Costa in terms of fitness.
Even if he's out a few weeks we should be fine in the short term. Falcao has not looked bad, and I have full confidence in Remy against swansea,Man city, west brom, and Crystal palace.