Judging by the picture up on Jane's, the ski jumps (albeit a model) appear to have far less of an incline than that of the QE Class so having a catapult wouldn't seem that ridiculous
Ridiculous? Maybe. Maybe not. I just don't see how anyone can design a catapult with a curved stroke. How can that be done?
And more importantly, WHY would one do that? Once you've committed to installing a catapult on your ship and building an aircraft capable of being catapulted, why bother with a ski jump at all? It adds nothing.
...appear to be presumably navalised T50s, which could be built for CATOBAR ops presumably?
Navalizing a land plane for carrier ops is not easy and has seldom resulted in a good outcome. Navalizing the F-86 Sabre resulted in the FJ-2 and -3 Fury, but they had lots of issues. The later FJ-4 looked the same but was structurally a complete redesign with a completely different wing. Going from the Hawk to the Goshawk is probably the only real success story and that required EXTENSIVE redesign. And that was for a basic trainer aircraft. Doing that with a high performance super sonic stealth design is certain to be
much more difficult. The F-35A and F-35C for example are considerably different aircraft with completely different wings. "Tweaks" just don't work. And assuming the Russians go with conventional steam catapults vs the new high tech electromagnetic catapults being installed on the Ford Class carriers, modifying a jet engine for steam ingestion is no minor undertaking.