I should probably start some new thread for psi, but I'm not gonna be 
posting ALL my psi changes just yet. For the record, almost all of my psi 
changes are just additions...new techniques, new enhancements/limitation, 
etc. I found David's work to be almost without a flaw (he's definitely my 
favorite sourcebook writer). Below you'll find a random handful of 
specific skill limitations and enhancements for certain psi powers. 

In addition, you'll find my brand new Exoteleport table. I'm very proud of 
this baby...for, while I've always agreed that (A) Exoteleport should be 
less powerful than TK at the same level and (B) ExoTP should bottom out 
at 25 lbs/level about when TK bottoms out at 250 lbs/level. BUT I do not 
agree that one level of ExoTP should limit the person to less than a 
gram. Therefore, I've started ExoTP off at just one level BEHIND TK, but 
when TK begins doubling, ExoTP quickly and smoothly curves into a linear 
progression. As such, ExoTP is much more powerful at lower levels (the 
intention), and a LITTLE more powerful at higher levels. Like I said, I 
think it's much better than just 1/10 of the TK table.

Energy Shield *2
  Special Skill Enhancement: In addition to locking onto energy
particles and funneling them away, you can channel those particles to
slow the momentum of incoming physical objects. The game effect is
that the DR gained protects against physical attacks as well as energy
attacks. It still gives no protection against mental attacks. +50%
  
PK Shield *2
  Special Skill Enhancement: You can "lock on" to the air around you
tightly enough to make the molecules partially refractive. The game
effect is that the DR gained protects against energy attacks as well
as physical attacks. It still gives no protection against mental
attacks. +50%
  
Autoteleport *4
  Special Skill Enhancement: Improved control. On a failed roll, you
do not go anywhere. You still lose two fatigue, and critical failures
still send you someplace unpleasant. This enhancement may always be
turned off if you would rather be anywhere than where you are. +20%
  
Exoteleport *4
  Weight is determined by the table below. If the jumper is carrying
an item by touching it while Autoteleporting or Combat Teleporting, he
can blink twice as much weight (e.g., a Power 15 jumper could carry
another adult with him.)
  
Power  Weight   Power   Weight
  1    1/8 oz.   11      8 lbs.
  2    1/4 oz.   12     15 lbs.
  3    1/2 oz.   13     25 lbs.
  4     1 oz.    14     50 lbs.
  5     2 oz.    15     75 lbs.
  6     4 oz.    16    100 lbs.
  7     8 oz.    17    125 lbs.
  8     1 lb.    18    150 lbs.
  9     2 lbs.   19    175 lbs.
 10     4 lbs.   20    200 lbs.
  
  Further increases in Power add 25 pounds per level.
  It is harder to "lock on" to moving targets. There is a skill
penalty equal to the subject's Move, -1 for every yard per second, up
to a maximum of -10.
  Special Skill Limitation: Reduced weight. Each time this limitation
is taken, the weight that can be blinked is halved. -10%
  Special Skill Limitation: Only with Autoteleport. You can only
teleport objects by touching them and carrying them with you when you
Autoteleport or Combat Teleport. Your weight limit is still doubled,
as above. -75%