As to retuning, there are definate limits to that. The changes in the tensions within the harp are so variable that you would have difficulties in keeping a recognisable scale if you start moving mre than 2 or 3 notes. Playing on the inner row is not actually difficult and when you are familliar with the layout, virtually anything is playable. I wouldn't even tackle it on a pedal. All of the more recent chromatic harps are X strung.
Theys are positively easy to play by comparison to a triple.
The Playel harp has a sound all of it's own and, having been llucky enough to play the Debussy Danses on one, I would never dream of performing them on a pedal harp. Oter harpists have refused to even try my triples, yet thoe that do, in the space of minuets can often adjust their vision to see all 3 rows at the same time and start finding chords and tunes. Be happy, Mike.