1. Looking at your suggestion, I wouldn't mind them being in the same universe but on different planets (even if I disagree with Hero Factory taking place on earth). One of the major problems with this is Bionicle G1, and how LEGO doesn't want to come back to that story. G1's popularity declined because kids couldn't get into the over complicated story, so I'm not sure if LEGO would come back to that story. As for Greg, I'm not sure if he'd do it. If you look at his track record of defining what's canon, he has a very "me first!" mentality, making decisions that contradict previous things before he was story lead, and straight up decanonizing entire books by other writers. Since he already stated that HF and Bionicle are separate, I'm not sure if he'd go back on his decision.
2. I also want more canonization contests. I'm just saying the current ones over on TTV are probably not going to be ending this year. And as for Phantom, I don't want a canonization contest for Phantom. If you look up Phantom on TTV, the actual creator of Phantom has resurfaced with evidence that they actually won the OG Dark Hunter contest for Phantom, but there was a problem with sending the pictures. So now they're trying to write a letter to Greg about it and see if they can get him canonized like it was supposed to be. The reason I think Greg could agree to this unlike in the point above is that Greg actually based Phantom's description on the photos.
3. I'm not sure how receptive the Bionicle community would be to it. If you look at the system Bionicle sets that existed, they didn't really like them. They also didn't really like CCBS (an amazing system they really missed out on). I'm all for new building systems for Bionicle, but I'm not sure if it will be popular among the community.