Since you seem to have done your due diligence, I'll help you out.
Having refined more than quite a few ounces of silver, here are some things I've learned:
Avoid silver chloride like the plague. If it can't be avoided because you want to separate it from lead contamination, do not form the diammine silver (I) complex in concentrated ammonia. Instead, wash the lead (II) chloride out with several portions of very hot water and save your ammonia. To make sure all the lead is out, check the last was with either sodium chromate or KI solution, a yellow ppt indicates Pb (II) and you need to keep washing.
If there are other metals present, dissolving in ammonia is desirable. Acidification after filtration with nitric or hydrochloric acid will return the silver chloride. Recall that a blue colour indicates copper contamination. Assuming you just want pure silver from your AgCl, you're best off to add some more base (i.e. NaOH) and reduce with a suitable reducing sugar, namely dextrose. You may also stop at silver oxide, and avoid the sugar reduction by simply heating until the silver oxide disproportionates (350oC is a good hold temp, then proceed to melt the silver powder).
Silver chloride should be avoided simply because it is very difficult to manipulate--making Ag2O from it is exceptionally troublesome if the AgCl is allowed to dry because it will clump up and you will find that it does not react. If you want to get it to silver metal without using the aldose reduction method, I suggest you utilize sulfuric acid and zinc or iron strips with heavy stirring. This will take a few hours, and if using anything but the purest iron and zinc, it will stink due to phosphine and hydrogen sulfide formed from impurities in the reductant metal.
I should advise that you should never attempt to melt silver chloride, it will volatilize and end up in your lungs and all over the place. If you do attempt to melt it, make sure you melt it with a gross excess of sodium carbonate with a slight amount of borax, which will reduce it to silver metal. Unfortunately, sodium carbonate is extremely aggressive on most refractory mixes, so your crucibles will suffer.
While I do not know your feedstock that you are obtaining this silver from, I can advise that the easiest method to obtain decent 99% pure silver suitable for the Thum cell is to use copper as your reductant (cementation).
Make a concentrated silver nitrate solution, put in a large bar of copper metal and let it sit. Periodically scrap the silver off the copper with a car window scraper. The shiny silver crystals collect on the bottom of the tank/beaker/drum. Do NOT introduce aluminum as it will add an extra step because you'll need to boil your silver with concentrated NaOH to remove the hydrous alumina that will inevitably precipitate. That is hard on glassware and a safety risk to your eyes.
Once you have the crude cement silver, usually about 99% pure, you should rinse well and cast it into an anode and electrorefine it in a nigh saturated solution of silver nitrate acidified with 30 mL or so 16M HNO3 per liter. I forget what current density I use, but an offhand voltage is about 3-5V depending on electrode gap/temperature etc.
Your electrolytic silver should run 999 fine or better (usually 99,97) depending on if your cement silver was free of palladium and nickel.
Hope that helps.