Should be fine, I've hung plenty of radiators before, just never worked with this plastic microbore pipe. I did replace rads in both bathrooms with towel rails earlier this year, no problems.
Regarding balancing - is it as important now that Evohome is controlling all the radiators independently? There is never a time when over half the radiators in the house are on at once, therefore one would think the system would cope with all the lockshields fully open?