I am sure that F1 linecards on Nexus weren’t able to support L3 functionality, so my query is does the F2 linecard (N7k-F248XP-25) on Nexus 7010 support Layer 3?
Yes F2 does support both L2 and L3 (plus some other additional functions).
You may check specifications here:
One restriction - F2 can't work with M1 or F1 line cards in same VDC, so F2 line cards should be set in separate VDC.
Hope this helps,