Corruption is a spectrum. Staying at his place? Foreign dignitaries did that before he was in office. They aren't just starting to do that now that he's Prez. So it's not really anything new. I don't like it, but it's not out of the norm. Same with his China bank account (that was closed in 2015). It's pretty normal.
Biden is taking money from foreign adversaries, using the office specifically for his own gain. If you don't believe me, check this out.
https://www.townandcountrymag.com/leisure/real-estate/a33809100/joe-biden-real-estate-homes/
You'll especially like the part where this is biased against my argument, however if you read it, Biden is doing the same thing you're talking about. Here's a quote from the article:
"During his vice presidency, he rented out a cottage on the property to the Secret Service for $2,200 a month." Using taxpayer dollars to go back into his pocket. That's just one example, my friend. The list of corruption is long. Do some digging.