In the FWTW department, there are at least a couple hops out there that give a good mango Falconer's Flight is one. The Just remember that more is not necessarily better, I measure my hops in grams not ounces. Changes I make are subtle. Flavor from hops is way more predictable than fruit.
Well if there is some yeast there, it will keep going and eventually it will ferment out. It is just that it makes different chemicals when it is in growth phase so for pils/lagers, I think it is best to ferment quickly, generally overpitch so the growth phase is really over fast. Especially these 2 LBKs that are only at 62 deg. (16.7 C) which is at higher end for the yeast (13-15 C is best.)
I regularly have bubble coming up at beyond 2 weeks, but I am told this is just the dissolved gas coming out. When they are still doing this at 3 weeks and I bottle they are often over-carbed, so I wonder. I am accurate with bottle carbing, using sugar dots.
I think they sometimes just slow down. I would wait until it pretty much stops. It is probably so slow at this point that you may not see daily change in hydrometer even though it is still slowly going on fermenting.
The mango wheat I have now is that way. I think it is still finding sugar out of the mango bits. but I think I may bottle it at 3 weeks anyway and only give the 750 ml's 2 cubes not 3. Hopefully I get not too many mango bits in the beer - lol.