Hello man,this is probably the best sun team I've seen and used (:P) so far.I can't see any major weaknesses but I'd like to ask you how you deal with some pokemon.
Terrakion: I think this is a threat that's not really well covered since you have no resistances to the rock type.Dugtrio can take care of it but it dies while trying to kill TTar(which is a common sight) you may have some trouble beating it.Venusaur can always revenge but can't really switch in,especially in a Banded Set.
Reuniclus:This may have fallen in usage but a Trick Room Set with Psychic,Shadow ball and HP Fire can be really annoying to face in case it sets up TR.It won't be easy for it to set up TR but if it does you're gonna be in serious trouble and you'll need the best prediction possible to beat it since it can OHKO or 2HKO almost everything on your team.
TTar + Hippowdon Sand Teams: These teams are not really common and I'm sure you have a way to deal with them because they're a bit more difficult to face,regarding the weather war.
Anyway,all the above threats(apart from Terrakion) are of low usage nowadays and even if you can't deal with them it's normal.I mean,there is no team without weaknesses and 1-2 severe threats always exist for every team.You got a luvdisc from me ;)