Here's an idea:

Features = Paint or ace suited, paint or ace pair, 4-straight
AWC = Additional Wheel Card

Pos 1-2 (UTG):
Low: Play A2 w. >= 1 feature or 1 ADW & 1 card >= 10 or 2 ADW
High: 4 card >= 10 w. 2 features

Pos 3-4 (EP):
Low: Play A2 (no 7,8,9), and A3 w. >= 1 feature or 1 ADW & 1 card >= 10 or 2 ADW
High: 4 card >= 9 w. 2 features

Pos 5-6: (MP):
Low: Play all A2, all A3 (no 7,8,9), and 23 w. >= 1 feature or 1 ADW & 1 card >= 10 or 2 ADW
High: 4 card >= 9 w. 2 features and all >= 10

Pos 7-8: (LP):
Low: Play all A2 & A3, all 23 (no 7,8,9) and A4 w. >= 1 feature or A45 & 1 card >= 10
High: 4 card >= 9

Rule 1: Don't call high hands first in, and raise them after 4 limpers
Rule 2: Raise first in or 1 limper except for high hands (see above) and low-only hands, which can raise 2 limpers.
Rule 3: SB plays like LP
Rule 4: From BB, call 1 raise with LP hands, re-raise with EP hands
Rule 5: 2 limpers promote position by one degree (e.g. with two limpers and hero in MP, LP hands can now call)

This is just off the top of my head, but it might make you tighten up and it does acknowledge position, which i feel is still significant.

Thoughts?

Cheers,

Smurf