All i have is rigid mtbs. For my 29er ergo grips have really helped with the hand numbing. I actually a 4hr enduro on the bike with hands that opened and closed with the new grips. I use cheap bbb ergo grips and they are good.
I have two wheel sets for the 29er. One is with tubular tyres and i run those at 20psi the other is 2.2″ tubeles s setup with conti tyres which are run at 25psi. Low pressures are must and 30 psi is way too high. Lower pressures improve grip, comfort, controlability of the front end. the front wheel also bounces less which is useful.
Rigid forks means your set up needs to be different to a bike run with a suspension fork. 2.4″ tyres are not a bad option either.
I do wonder if head angles should a be bit slacker for a bit more control.
As for not being able to ride a 29er rigid at speed well that not true. Had a few top ten finishes in mtb races on my 29er. In the thetford winter series 4 hr i have had a 6th in december. Over rough ground the only thing that lk,its your speed is you, its not thw bike. You have to careful about your lkne though. If i was fitter i could do better. Suspension though is an expensive way of spending money. Stick with rigid forks you will get used to them if you give it a chance. It a skill that has to be learnt and you do have to toughen up a bit.