I'd pass on Aguero too. Unless we also get Haaland and Aguero would be his backup (preferably on a 1+1 year contract) but that's unlikely. Alternatively, if we'll sign a youngster like Malen who could (hopefully) eventually take over as our future striker then I also wouldn't be totally against signing Aguero until he's adapting. But having Kun as our only #9 (and so probably a guaranteed starter) I'm not a big fan of.
I'd take Wijnaldum if he accepts a 3-year contract at most (2+1 would be even better) on reasonable wages. Yeah, we have Ilaix but do we really want to have two kids younger than 20 as our starters alongside FDJ who is also still relatively young (he still has some things to improve on but he'll be 24 in two months so he might enter his prime years relatively soon)?
If Messi leaves and we'll have a full rebuild season next year then maybe but if he stays and we want to be competitive (which is what I think Laporta wants) then I don't think that's really a good idea. FDJ-Pedri-Ilaix midfield could be great in 2-3 years but next season might be too soon for Ilaix. If he's ready to take over as a starter and he'll show that (like Pedri did) then great but we shouldn't rush and possibly ruin him.
Probably the only alternative to Wijnaldum is keeping Busi as a starter for another season. I prefer Gini whose legs are not totally gone. My plan would be having Wijnaldum as a starter next year with Ilaix coming on as his sub (he could also play in the Pedri role imo so there would be enough minutes for him) then if Ilaix will develop as expected they could share their minutes around 50-50 a year after and in third season Ilaix takes over as a starter and Wijnaldum becomes an impact sub (or if age will catch up with him we could just let him go for cheap like we did with Vidal).
A midfield like Pedri/Roberto - FDJ/Busi - Wijnaldum/Ilaix wouldn't be too bad imo (I'd prefer to keep Pjanić as a backup over Busi but that's just me and probably not the right thread to discuss this). We'd have a younger and a more experienced player in every position but in opposite to the EV years now we already have two youngsters who are fully established so I think pairing them with someone more experienced would make sense.