[Naumoff]

There should be a fiber washer betweem the bowl and the fitting.
No teflon tape.I doubt you cracked the bowls unless you really wrenched on them.

mr0077 is correct. About the flare fittings. Back it up with a wrench.
Check the surface of the flare fittings. No dope, thread compound, sealer or teflon tape. It shoud seal without this. Trust me on this, I am a plumber.

Sounds like you are on the right track with the linkage binding problem.