I have not read through entire thread so if this has been stated, I agree with who stated it.
First, I don't think the issues is all about James and Irving. I honestly think this has more to do with Waiters. I have been watching a lot of the Cavs games (preseason and regular) and I noticed one giant issue.
Right now they have no one who wants to play in the weakside corner (who starts). Some has to fill that. Waiters is not willing to fill that. Love is in the pick/down low/on the wing. Irving and James have been filling that spot.
James should not be operating out of the corner unless he is kind of winded and wants a short beak without coming out. Teams should not have their PG in the corner often because it can lead to fast breaks. They really need Waiters needs to fill that spot.
Ultimately, they are not going to be nearly as good as they can be until they get someone to accept that role. Miller and Marion will do it, but I am not sure they are down the stretch players at this point of their careers.
Irving and James may be having a personality clash, but that will work itself out with winning. Getting someone one of these guys to be relegated to weak side corner floor spacer is the hard part. I kind of think that Waiters may have to get traded to make this work. Not sure who the Cavs can move him for though. Maybe Afflalo, if the Cavs give up a pick. The money does not match there would have to be throw ins.
I wonder If Ray Allen is planning on jumping out of retirement half way through the season and filling that spot.
Floor spacing seems to be there biggest problem on offense.
On defense they have physical limits. I think James has been worn down about the last few year with the minutes and load he has carried. Waiters and Love will never bee good defenders. Not sure if they have a team that will bring the defensive energy and skill every night in the regular season. That can be dangerous. Not all teams can just flip the switch once the playoffs start, and this Cavs team does not seem like one that will be able too. They have a lot of players who are young and don't really understand what it takes to win.
Final thought. James is still the best player in the league. Even with all of the minutes he has played. It is almost impossibly to think anyone in the East can get past the Cavs just because James is there and they do have talent.