Well since you have a turntable/arm that does not allow for VTA adjustment its good you are not too concerned! Otherwise you would have to upgrade yer hardware, and frankly most people love the music that comes out of their Rega setup (myself included, although I just sold my P3 because I no longer needed a second 'table).

Two things about VTF: first, recommended VTF is usually a starting point, adjust by ear after that; second, many of my turntable-lovin' friends (and myself) invested in one of those portable digital scales to use for setting VTF. I forget the model I bought and its in storage right now, but you should be able to get a good one with two decimal place accuracy for about $60. Third (I know I know I said two...) after you set your VTF do one more round of cartridge alignment because a change in VTF results in a change of alignment (because the stylus deflects more or less according to the VTF, natch).

You might cast about for a local vinylphile who can come over and give you some tips or help out. You could also subscribe to the phonogram equipment email list where some serious expertise resides - send email to "majordomo@phonogram.net" and in the body of the email put

subscribe phonogram
subscribe equipment
end

Say "Hi" and "Roger sent me" when you get there.

Roger