We don't know what the Russians have had in the air and regardless the Mig 29 is a perfectly respectable aircraft, designed to go up against and in some ways superior to the F15. Particularly in the hands of experienced pilots, which one assumes the Ukrainian air force has.
No, putting NATO forces in direct confrontation with Russians would be fucking mental. Exactly the sort of escalation we should avoid like the plague. Much better to just subtly and not so subtly equip and rearm the Ukrainians and help them attrition the Russians into seeking a ceasefire, de-escalation. Which, f**k my hat and call me Susan, is what they are doing.