If you want a range, bet the range. Your ovens are old, anyway (not that new ovens are necessarily as good). It shouldn't be too hard to make a temporary cabinet for your drop in that could be switched out for a freestanding range if you leave a little margin, but the measurements of the specific appliance are necessary for a slide-in, and the counter top has to be fitted around it and all.

You can transition from white to stainless a bit at a time. The two look okay together, so long as they both look okay in your kitchen. If you don't like the white, however, don't bother with the white warming drawer. It might be worth checking to see if the white Dacor can convert to panel. My "panel ready" Monogram warming drawer is just the stainless one which you can take the front off of, that comes with a red plastic disk to put over the light if you want to drill out the custom panel.

Re fridge drawers, it depends on your usage. I have them for my prep area, for produce for cooking, milk and butter for cooking, and sometimes for large pots of things that have been cooked. I have a 30" Miele fridge (tall, integrated) as well. Other people use drawers in a snack area for the kids to get their own drinks and snacks without opening the main fridge, or a bar/coffee area for beverages. Another few put them in the breakfast room for things that are used at the table, like milk, butter, juice, condiments, etc.

Perlick makes great big horizontal refrigerators that have quite a few drawers. Same capacity as a standard fridge, including some freezer drawers. Some people just put in a series of drawer units. This is done when they don't want uppers to block views, for wheelchair bound folks, etc.

If you truly have a limited budget, however, I'd put the money toward the range you really want. You can probably get a good price for the nearly new drop in, if you sell it. Refrigerator drawers are expensive! They're a great convenience, but not necessary, especially if you have another refrigerator as well.

You've got a new cooktop and working ovens - I wouldn't switch to a range at this point if you're on a limited budget. It will take a bit of remodeling if you switch to a range in the future but it can be done.