You mentioned you had an alignment done, and you don't appear the type to have used a 'toe-n-go' chain.
That said, I'll offer my FWs have had the squishiest and most vague overall steering of any car out there, including my wife's Tribute!
Now years back when trying to cure cloverleaf jerkover I did not feel appreciable difference when unplugging the Variable Effort boost potentiometer, thus sending system into fulltime/full boost (it's at the firewall). There's a very detailed thread on the differences between CHEV-Buick-Cady pumps (Joel?), and for a car that's already had previously "wrong repairs" it may be yours had an incorrect replacement.
Not much else except box and caster points above.
\'96SS SOB: SSRI, Herter Tune, Tri-Y II, , 3000 Edge, F/HO bars, METCO extendeds with CV MMC, Bilsteins, currently Vredestein Ultrac Sessanta (315/35 rear). Finally, wait for it... LT-4 knock module!
\'96FWB BUW-Butt Ugly White: PCMPerformance tune, HDFA w/ swissed filter, 1/2 SLP s.s. catback with H- and Flow Super 50s, oem opti rebuilt 3 times, SS Bars, METCO LCA, Airlift 1000, Monroe SS, PowerTrax No-Slip, CTS wheels with +1 rubber. Finally, yes again... LT-4 knock module!