A graft looks like a gnarled fist just above the root. If you bought your Don Juan at a regular retail nursery or garden center, it is probably a graft. If the thin canes are coming from below the graft, they are from the rootstock and should be pulled off [to remove the eye]. If they are coming from above the graft, from the same point that the other canes emerge, then they are just week new canes and can be pruned or pulled off. Keep only nice firm thick juicy canes and just one or two of those.

Someone else with voles. I've been battling them for years and they are the only thing that has ever gotten the best of me. If you create ideal conditions for them to thrive, you will probably get them and it is a challenge to get rid of them. And what are ideal conditions you ask? In their natural state voles live in the soft composty forest floor where the soil is basically compost. The don't live in hard dirt or are they very deep. They live in a maize of tunnels where they eat roots. They love rose roots. I've seen them kill a healthy rose in no time at all. The rose starts to wilt and soon it falls over. You pull it out and there are no roots... just a stub. Most people don't have a vole problem because they don't create the ideal conditions for voles to live. I do because my beds are just like the composty forest floor and one year I lost about 60 roses. Some entire beds. What can you do? You can dig them up, flood them out, impale them, or try to poison or gas them. I made an impaling devise to impale small areas and not miss them. You need to cover the area entirely to make sure you stab every vole. You need to clear the area before you plant again. You can try to protect the roses from voles when you plant either individually with wire or the whole bed. I surrounded some beds individually and I protected the entire garden with wire mesh fence. I didn't vole proof it but the damage has been minimized. It sounds like you have made a good vole environment so you will have to get after them. As for Don Juan, it has nice form but it is a bad climber. I would replace it with something else. Good luck.

I don't have DJ so I can't say what is typical but that looks like it's a new rose and the first blooms on any new rose are usually smaller because the plant and the root ball is still so small. It takes a rose several years to mature and climbers, in particular, can take at least 3 to 5 years to reach maturity. Besides time weather conditions will also have a lot of affect on bloom size. So if you've had a cool, damp spring that may be another factor. Your plant looks wonderfully healthy and happy so I would not be worried about the bloom size at this time.

Just stick it in the dirt. I have 2 cuttings I stuck in pots last year, I found they rooted easily with no special treatment other that watering them. They made it through the winter with no protection and getting very big and have been blooming all spring and summer just like thier mothers.