Generally speaking, extreme heat means faster growth, but if you're underwatering due to your situation, that's likely to have more of an impact than feeding, so I'd stick to applying a 100 ppm N solution once a week.
I really cannot tell how you have them organized very well from those photos, but as far as the terminology goes, the order is:
- Genus
- species - cross or grex if it's a hybrid
- variety or cultivar
So dendrobiums A & B are of the same genus, but (if hybrids) are different grexes.