I know a lot of founders whose companies are allegedly worth a lot on paper, but cash on hand is very limited.

I wonder how the wealth tax actually works. Do I want people to invest in my company if that's just going to increase the valuation and my tax bill? Surely there must be some exceptions...

This year, quite many have actually chosen to move from Norway to Switzerland, probably due to taxes

Not a problem for a startup surely, they have debts not wealth.