I can probably help answer a few of these things, but, I need some clarification, so, as you ask questions, please refer to the terminology below.:
1. Progressive lenses have no line.
2. Bi-focals have 1 line.
3. Tri-Focals have 2 lines.
4. "Transitions" are lenses that darken in the sun and get lighter inside, they have nothing to do with your lens power.
Progressive lenses will always have some manner of "hourglass" shape as you "progress" through ever increasing + power to get to your full reading add power. Think of an hourglass, now, as it applies to lenses, you can only see clearly through the part of the hourglass that the sand can be in, everything outside the hourglass is "soft-focus" or blurry. Typically, the more you spend on a set of progressive lenses, the further into the periphery the "soft-focus" portion of the hourglass can be pushed, or, the wider the "waist" of the hourglass can be made. There are dozens of progressive lens designs and many of them have multiple manipulation options that an optician can choose to help customize the lens for your specific needs.
Bifocals have 2 powers, and 1 line separating your distance, and your reading. There is little to no peripheral soft-focus, but, if you're catching the line you'll see double and one of those images will be significantly out of focus.
Trifocals have 3 powers and 2 lines. Your distance vision is on top, your "intermediate" say our to 30" or so, like the distance to a computer screen will be the middle, and the bottom will be your reading for up close like reading a book or your phone.
Start your questions under the premise that NOTHING is going to allow you to have your 20yr old eyes back short of a multifocal IOL and few are going to implant those prior to your needing cataract surgery.
