First, the play may be due to any number of things loose under the front
end, but if all the tie rod ends, ball joints, etc are tight, then suspect
the steering box itself.  The slack in the steering gearbox is adujstable.

Second, I've never done a swap like that.  Also, I've never seen wiring in
place in the doors that didn't have factory power locks.  If you want to
retrofit power locks, you could do a junkyard swap, or you could go to
someplace like lmctruck.com or jcwhitney.com and find aftermarket kits.

Third.  Seat comfort is highly subjective.  If it were me, I'd look to find
a nice pair of Ford van seats that you like better.  My 2003 and your 1994
are essentially the same van body-wise.  My captains chairs are comfortable
and have power adjustments and lumbar support adjustment.  You can look at
those catalog sites I listed above and find aftermarket seats if you really
want to go that route, but my experience is that aftermarket seats don't
last as long or wear as well as factory ones.  If you look around ebay or a
junkyard, I think you'll find newer Ford seats that you'll like better.

CJB