Looks most like a bonito than any other member of the tuna family.

For me, fishing season will end when they start filling in my grave!

The banana thing is a superstition. Bananas were cut in large bunches, put in boats and shipped to the USA. Tarantulas live in banana trees amo.ngst the bananas so there were many instances of mates getting bit by tarantulas

As to your question about a size10 boot, it will be enormously too small, that is if you buy stocking foot waders with neoprene feet. Your boot/shoe should be 2 full sizes larger to make room for the neoprene.
If you buy one of the less expensive and/or wader that has the wader and foot made with the same thin material with no seam between them your size 10 boot should be just about right.
All that said, I would recommend, as others have done, that you go to the store and try on the particular wader you are looking at and try putting a boot over the top of the wader.

I am 72. I am going pheasant hunting this morning, but I also go fishing whenever I can which is usually 3 to 6 times a week. Boy is retirement great!

I am left handed. When I first started fishing almost 70 years ago all I had was an old knuckle buster. I took it out in the street and learned to cast with it. It had a right handed retrieve. Then along came spinning reels with left handed retrieve. I now use both. I cast conventional/bait casting/level wind gear with my left hand and I cast spinning gear with my right. Just the way I learned, and I never had a problem about switching hands because of it.

I learned how to cast a fly rod (sort of) in 1970 while stationed at Barksdale AFB, Bosier City, LA. I didn't use a fly rod again after leaving Barksdale until I joined a group here in Cheyenne. The group is a nation-wide non profit called Project Healing Waters Fly Fishing. They helped me make my first fly rod and taught me about fly tying and then took me fishing. My first trip I managed to hook and land 2 pretty nice trout. Since then I have been on lots of trips. I usually catch a few trout but quite often all I catch is a suntan or a bit of rain.
I guess what I am saying is that I do not have any expectations when I start on a trip. If I manage to catch fish, it is a bonus as I feel that being in the outdoors is one of the greatest experiences around.

Lead head jig with a twin tail grub in root beer color. Used to catch calicos in the kelp beds with this jig.
Also a lead head jig with a squid strip worked great, caught my biggest calico almost 12 pounds at the dock, on the jig and squid rig fishing the inside of San Clemente Island.

I must say that I absolutely love light tackle fishing. I have spooled either 4# or 6# line on all of my freshwater outfits. And when fishing in the salt, I take rigs set up with 10#, 12#, 15# and 20# line and have caught tuna to 60 pounds on the 12# line and Giant Grouper to 65 pounds on 8# line (this one from my surfboard.)
What I am trying to say is that if you have the patience, a reel with an excellent drag and the line capacity on your reel, you can land bigger fish with freshwater gear.

Since you didn't mention where you are located, I will assume that you are somewhere east of the Mississippi River.
I live in Cheyenne, Wy., which is considered trout country. But right here in town we have 2 lakes (ponds really) that hold good populations of Crappie, Large Mouth Bass, Blue Gill, Catfish, Yellow Perch and of course trout. Also, within 120 miles of my home I can catch Walleye to 16 pounds, Small Mouth Bass to 18 inches and several varieties of trout from 1/2 pound to over 20 pounds (depending on species!)
So to answer your question, yes the western lakes do hold lots of pan fish.

I would think that if your budget allows, go with the ultra light.
The medium light will work OK, but the fish you catch won't seem to put up much of a fight on it.

Let me say this: A boat is a hole in the water that you throw all your money into!
That said, I own a 14 ft. Tracker Super Guide V-14 with a 25 horse Mercury outboard on it. I also own 2 float tubes and 3 pairs of waders. And I still have days that I won't use any of them. Each of these methods of fishing can be very satisfying, and productive. And if you haven't thought about it as yet, don not forget the floatation device(s) and something to make loud sounds with as there are still boaters out there who think they own the water and do not or will not look out for you.
If you learn the different methods for each type of fishing, your enjoyment will increase tremendously.

For salt water fishing the box shown will not be very useful as most of the artificial lures used in salt water will barely fit in the 2 long slots on the top shelf of the box. As a previous post suggested, get a few plano tray type boxes with adjustable lengths and fill each box with specific lures for the type of fish targeted.

“He has gray hair, wears glasses, has a potbelly"

Wait a minute!!!! I resemble this remark!!!!

Thin Mints and Thin Mints with a stinger, AKA articulated Thin Mints should work quite well in Colorado. Never tried them in the salt but they may prove very good there also.
I don't recognize the fly in the picture so can not comment on its catching capabilities in Colorado, but looks as if it should do very well in the salt.