zippi;
I suggested you start at ".020", did not say that is your setting, .020 will usually be safe to start as your cam's settings are unknown.
I also suggested you try an "Old time way of adjusting valves with vacuum gauge"; back off till they tick (at idle), tighten/loosen slowly to highest idle vacuum, run the rack (all valves) several times adjusting slightly to get highest vacuum or until there is no change in vacuum readings.
Believe it or not, your vacuum gauge will tell you the valve clearance needed by using the above method then measuring the clearance with a feeler gauge for future.

JMHO; keep in mind by your own words "you have not done this for a number of years", and with the problems you're having, I would not recommend the one revolution (#1tdc - #6tdc) method for adjusting valves (in fact I don't recommend it at all). Use the two revolution method, it assures the valves for the cylinder being adjusted are actually closed.

Further, may I suggest you slow down and try one method at a time, and not combine several different methods together.

Also there is a strong possibility, "Mr. Techinspecter1" was correct when he told you your cam may be going flat. I know it's not what you want to hear, but check your oil for metal (looks like metallic or metal flake paint).

And PLEASE, as you go forward, keep a log of all the details about your car's specifications, motor, running gear, oils, plugs, fuel, exc.. You will appreciate it in a few months when you have forgotten, and the next owner will too.