mig-29SMT is still a better plane than the current older mig-29 in Russian service so as i said its likely they will get rid of them before the SMT. I agree Iran woulod be better getting rights for mig-29M and Su-30.
True, but the best feature of the MiG-29SMT is not its modernised electronics or improved weapon range, it is the reduced costs of operation and maintenance...
The MiG-29M2 should also be much cheaper to operate but it is based on a new more modern airframe, and the brand new state of the art components that make the MiG-35 better can be fitted easily because it uses the same airframe.
I have said before and will say it again... I would put the MiG-29M2 into production and make 150-200 of them, but I would also buy 50 MiG-35s and use them operationally... I would give it a time period of perhaps 3-5 years and then get the operators... pilots and crew to decide which features of the MiG-35 are worth the cost and upgrade the 150-200 MiG-29M2s with those features... after five years of course MiG will have come up with new systems and new weapons that of course being new will cost more but be largely unproven... I would probably buy 25 sets for half my MiG-35s and use them for a bit and then decide whether to upgrade all the MiG-35s or all the MiGs, or none.
The MiG-29M2 is a bit like an F-16... it is a useful cheap fighter that can perform a range of roles adequately... the MiG-35 is like an unstealthy F-35... that will be much cheaper to buy and to operate and able to carry a much broader payload.
As for the Mig-31 as i said Russia has quite a large number of these in storage and although they may use some for parts and bring a few back into service they do still plan long term to replace and i sure they wont use them all in storage so i guess it wouldnt hurt selling some to Iran it would clear a few out of storage and Russia would also benefit from parts, maintenance, and missiles for the aircraft. And on the flip side Iran gets a decent aircraft.
From a Russian perspective it is useful to have aircraft in storage available if needed. If Iran wants to buy some they will likely need new engines and a complete overhaul and upgrade because these are mostly from the cold war optimised for Soviet operations within a Soviet air defence system.
What weapons Iran wants to buy from Russia is another matter... they might want the R-33 or they might want the R-37, or they might want to make their own missile. Of course they might want to make a new missile with Russia as a joint venture... we keep hearing about the KS-172 with India but never see any actual progress... Perhaps Iran might kick it in to reality and load up MiG-31s and F-14s with it...
WIth the MiGs engines back in production perhaps an engine upgrade for the F-14s to make their own sort of F-14D model?
As for the Su-24 yes you could upgrade it to be semi multi role, but would the cost be worth it, i remember sometime ago we talked about upgrading older aircraft and was it worth it.
It really depends on the condition of the aircraft... a swing wing aircraft is tricky... they had to build an entirely new Titanium forge to allow them to make the enormous titanium box structure the Blackjack needs for its swing wing design... perhaps they could do the same for the Fencer and make it lighter and stronger... able to carry more payload?
Who knows... I suspect the older Fencers will be scrapped... they are getting useful and good use in Syria... and any problems in Afghanistan they could use them there too or in the former soviet republic 'stans if that is ever needed... but the Backfire could probably do the job and do it better. And now of course the Su-34 has matured and can also do the job too.