pcmancini,
To check your neck relief:
fret at the 1st fret, and at the fret where the neck joins the body.
Halfway between these 2 points, the distance between the top of the fret and the bottom of the string should be about the thickness of a playing card.
If the gap is too large, loosen the strings, and tighten the truss rod gently and slowly (about a quarter to a half a turn).
Re-tune and check the gap again.
The neck can be damaged over time , and may not respond to truss rod adjustment if you neglect to do this.
Some day you may want to sell the guitar, and with a warped neck its good for nothing but
slide.
Check your action, and adjust the saddles to your requirements.
(I like my action high enough to be able to fret behind the slide for chord extensions. BUT, If the action is too high, when you fret a note it will pull the strings pitch sharp).
I also use .013<.056 w/open E, and it adds a lot of tension to your neck.
If you are planning on using open E exclusively on this axe, try custom gauges.
Try dropping the 3rd string down from say a .022 to a .020, the 4th from say .034 to .030 and the 5th from a .044 to a .040.(Most music shops sell single strings)
This will even up the tension across the six strings, and make it a lot more playable and well balanced.
Hope this helps.