Hi & welcome to the forum, & to the wonderful world of classic motorcycles.
All BSA A10's are generally reliable as classic motorcycles providing they are looked after well. Yours sounds to be a nice example of the slightly faster Super Rocket.
As your magneto is working perfectly I would not change it. As regards the advance/retard, providing the bike is timed correctly (which is normally done on full advance), you should really only need to retard a little for starting, or if your engine starts to labour on hills or in slow heavy traffic. Otherwise you will normally run fully advanced. You will get to know the A/R position for different running conditions by how the engine sounds & feels as you are riding.
Your starting procedure for cold starting sounds about right, although you may not always need choke, flooding the tickler is usually enough, with the correct A/R position. When warm or hot just tickling the carb. should be fine (again correct A/R position).
One other tip worth doing, is to regularly look in the top of the oil tank after starting, to check that the oil is returning nicely.
Have fun.