emin-j,
just a realisation since Zaal that what i call whole spice is in fact "chef" garam. i've posted about using a muslin bag and subsequently spice ball for some time. parker21 also added the water infusion method.
the ghee used to be marg. it was chriswg who put me onto switching from the marg. the marg came from the ashoka base - which for me has far too much marg in. i've not kept record but think the optimum ghee/marg was 60ml in 800g onion which equates to 3L base.
on 60ml being chef spoon then your idea of using 1 off in 6L sounds a good starting point. the ghee is much better than the marg as it produces the same effect but not a sort of sickly Taint associated with the marg.
on the chef masala i've not experimented as 1 tsp seemed to work. previously in the spice ball went 4 off cardamom, 4 off bay and 1 off anis. the tgad or Zaal method enables more depth of taste by adding in a greater depth of spice. i also use it now post fleet5 in my mix powder. i've used in pilau rice for some time too.
on the amount what i look for is the taste in the oil. just taste a bit when it surfaces. it's possible that more could be added but i feel i have no need to experiment as the 1 tsp does the job. everything in curry of course needs to be in balance and too much would be as bad as too little.
i can't really say that either of these additions make a 'silky' look though.
ps try a 1/2 chef of base to help out with the singe - may help - it's what i do (see spice frying trials).
base link may be of use in terms of the general principle to be applied to all/any base:
http://www.curry-recipes.co.uk/curry/index.php?topic=3462.0