I bought Pan Am in 1967. I think it was in the high 20's at the time. Bad buy! Snce then I have done pretty well. I am not sure I understand your aversion to cash. I don't pay much attention to major brokerage houses recommendations - but in the last 40 years I don't ever remember hearing a rec for 0% in cash. Why do you suppose that is?
As far as your diatribe on Beta - it is guilty of falling within the realm of TA. It is just another historical measure which as you point out have proven to be unrelaible predictors of the future
Professional Money Mangers get that title because they get paid for managing money , not necessarily for making it. It's a statistical fact that some managers will outperform the market in both the short and longer term. I choose to believe that those on the right tail are just lucky. I might be swayed to let a "professional" manage some money if they would guarantee future performance will be based on past results.