There are issues with your "solutions."

1. Mods don't always delete RBPed posts/threads:
Suggesting RBP for the sake of having your posts removed, IMHO, only increase the workload of our volunteer mods. I've done my fair share of RBPs. However, I don't personally recommend it for THIS purpose.

2. Theoretically, per TOS, one individual can only have one FT handle. If your 2nd handle suggestion would have a similar effect to change one's FT handle, all the previous posts will still on FT and the previous posting history will be transferred (or attached) to the "new" handle. To my knowledge, there's at least one FTer had changed her/his FT handle recently and all the post count "credit" from the previous era is now under the new handle.

However, if cancelling one's FT account will automatically delete every post one ever makes on FT, that's another story.

The question then becomes: "would FT admin grant cancellation requests, knowing say FTers with the very intention to start from scratch under a new FT handle?"

Or is there another more "constructive" way to address OP's concern? I don't think OP's getting any "positive" response from the admin (yet).