Clean the tank with vinegar and rinse very well. I would not soak the rock in anything other than warm (hot out of the tap) water. Rock can absorb liquids and they can then leech over time. A stiff brush to scrub it under the hot water is fine; I use an old manual toothbrush saved for aquarium use (works on filter parts too).
Moving the water is counter-productive unless the tap water parameters in the new tank are vastly different from the existing tank the fish are in. I always set up new tanks with fresh water using a water conditioner of course. I do a major water change in the existing tank before moving the fish over. The new tank obviously needs seeding with nitrifying bacteria or live plants; if enough of the latter, that will do it. And any wood or rock from the existing tank moved over when or just before the new tank is filled (with dechlorinated water) will transfer bacteria too, do not wash or rinse the wood/rock transferred over.
You have some problems in the proposed fish stocking. Silver Dollars are not good companions with angels, and they eat plants; plus, there is not sufficient space in a 35g for a group of SD.
Leaf fish are predatory, so no small fish; also, very shy and retiring, needing lots of cover. And not good with angels, both are territorial. One species is in our profiles for more info, click the shaded name,
Ctenopoma acutirostre.
The shoaling fish you mention need larger groups to be better off, so that will take up the space quickly if you keep all of them. I would remove the minnows, they need much cooler water than the other fish to be healthy.
And before anyone says it...yes, the fish may "seem" to be OK now, but that does not mean they are.
Byron.