Not that you care or anything but several of the things you said seem to be clearly false, hearsay, or rumors.
"Shakes hands with ghosts" was one that is clearly false. (He pointed with his hand.) "Sits on chairs that do not exist" is another one. "Poops before the pope" was a rumor..... and even if true, loss of bowel control does not necessarily mean loss of mental acuity.
"HE was found mentally competent" references yet another one... that "Biden was found mentally incompetent to stand trial" by the special counsel......which is false. That is a specific legal claim that I'm pretty sure can only be made by a doctor and/or judge.
The special counsel simply thought they wouldn't be able to secure a guilty verdict. Thinking that a jury would believe him if he said he forgot is not the same as being declared legally / mentally unfit.
Trump's documents case against him is a bit stronger. The "I forgot" type defense might not work if you had the National Archives ask for months for the documents and had to have your house raided by the FBI to get back documents that your own lawyer claimed you gave back already. Might be easier to secure a guilty verdict in that case.
Others you didn't mention but other people here have............."sniffs children", " 'drove' an F150 with 2 steering wheels", "teenage Ashley Biden showered at night out of fear / to avoid Joe" , "banana republic" and so on....
It's like the right is constantly trying to build this mountain of bullsh*t against Joe Biden. Seems desperate. Maybe they don't think they can win on policy.