The frequency error is not a problem at all - it’s just annoying if you like whole numbers!
I think it’s important to remember also that the frequencies reported by RBN stations are not 100% accurate and they don’t seem to be rounded up. A frequency of 7.02999 would still show as 7029.9, so your rig might be closer to ideal than you think.
I have also noticed that temperature can have an effect on the reference oscillator - calibrating in a cosy lab might lead to a frequency difference on a cold summit.
Regarding calling other stations - the offset is fixed so just tune the station for the best reception and call, the TX frequency will certainly be within other station’s pass band, and I’m sure they’ll have RIT too!
My first run MTR (kit, two band) has a small frequency error, I didn’t have the means to calibrate it exactly at the time of build. I just live with the error, it’s around one click out, so less than 50Hz. It’s simply not worth going through the whole calibration sequence again.
I found that the cheap frequency counters available via Ebay are actually pretty good. I had the 6 digit version, but there are also 8 digit versions for a small increase in price. My counter is now built into an SW-40+
Example listing -http://www.ebay.co.uk/itm/322792559519
I also have an MTR habit - I have three!