I agree with you on various points but I think there is a few misunderstanding here.
Firstly, in FaOI, there is a rule that the audience cannot hand a gift to a skater while they are on the ice. In FaOI, there is no time for a skater to collect gifts between performances. Besides, there are no boards between the ice and the audience, so allowing it is a bit dangerous both for skaters and the audience. FaOI organizer always asks fans to hand the gifts by putting them into the gift boxes until the end of the Zamboni time before the 2nd half.
So, Johnny is breaking a rule when he receives the flower crown during the finale. However, I think it is probably overlooked because the giver seems to be more than a fan for Johnny. I have seen photos of Johnny and her having dinner with other skaters on Johnny's Instagram. The tradition of giving/receiving the crown can be traced back to Vancouver 2010, so it may be seen as a tradition between longtime friends or something.
Secondly, Yuzu has never said that he doesn't accept gifts from fans. He just stopped reacting to each gift publicly to avoid troubles among fans. He half-jokingly said that if he gives a fan a special treatment, other fans may leave him/her out.
When he was younger and had fewer fans, he sent hand-written thank you letter to fans who gave him fan letters and gifts. It wasn't rare to see him using some of the fan gifts until several years ago. Pooh is one of such gifts given a long time ago and now his comrade. I doubt any fan (whether older or newer) would attack Yuzu or the giver for Pooh being there. I doubt any fan would get mad at Yuzu for how he handles the gifts now either because obviously, it's the best he can.
Since I don't know what happened between Johnny and Yuzu's team, I don't want to comment on the photo incident itself. I don't feel that I need to anyway because I know Yuzu is in no way afraid of wearing flowers (see FTT costume) and if he and his team asked Johnny to take down the photo there should be a good reason to do so. It's too bad that Johnny wasn't happy about it, but since they are two different persons there can be a disagreement. Also, Johnny might have had a good reason to act that way.