They already offer Pak fa for the export. They were ready to give the Su-35 to Australia. Of course they won't export their top technology. Russian make always an export version which has pretty much nothing to do with the domestic variant.
Of course they will export the new mig, Mig-41 or LMFA, they are near the bankrupt. Since the issue with Algerian Migs, no country has bought them. Egypt is buying from every one because they need independence from US supllies and pressure.
Su-30/35 won't be exported in the future. Countries which can buy this type of fighter will go for Pak Fa, F-35, J-35. Look at all the 5 gen fighter projects that are done (Japan, US, Russia, China, FR-Germany's future aircraft).
Don't think because one of your exported aircrafts could be taken and studied by US, it will affect your defence. Now you can design an F-15 in CAD software and see it's limits. The electronics, radars and IFF, are not the same.