Posted: 26/07/2016 at 18:45
1. Yes, always sensible to replace something that isn't working for something you like.
2. Petunias do like warmth. But when the baskets were failing had you fed and watered them? Did the new petunias get new compost?
3. Looks like a Philadelphus, does it smell nice? Probably needs pruning, a feed and some water, unless, of course, you are having lots of rain. Petunias don't like lots of rain.