Hi Dana,
Yes I totally agree with your explanation about Switch cast, it is most fundamental style of Spey casting. Anchor position is the just matter of the direction you want to cast, unless you want to cast more than 90 degree of direction change you don�ft have to bring Fly up above your position. Fly just to be slightly above the direction of cast to avoid tangle on line.
Regarding to the question about ratio of top hand and lower hand, it is not really the matter of style. Most important point is that fishing comfortably with Speycast, after all day fishing shouldn�ft get so much tired and without trouble. I found my style and Tak�fs style (This originally come from Jim Love who is excellent local angler in Grantown-on-Spey. He is great caster and instructor too) to make all movement of Speycast easier. You could control line lift and Anchor position only by upper hand so less risk of variant on Anchor position. But important, holding grip I put more firm on lower grip let�fs say 70% on lower grip and 30 % on upper grip so I don�ft get any tiredness on upper hand. Just use upper hand to control of rod movement.
In addition to this we could utilize total rod length by not moving lower hand. 15�f rod we could use as 15�f. If you pull lower hand 50%, 15�f rod becomes 14�f due of moving up fulcrum, it loose some energy of rod. Answer to your question I don�ft pull lower hand at all, even on the contrary some time I push lower hand too. (Push Upper hand 95% and push lower hand 5%) This will create extra length on rod because the fulcrum moves farther down. I also tried using both styles �gupper hand push and lower pull�h but concluded use of upper hand only, it makes me easier and comfortable fishing all day.
However good to know different casting style, so try it once then decide whichever suit you for good fishing.
:chuckle: