Earl,
I don't understand yet if you would prefer a large blade (your Spitfire) combined with a medium sized blade (like a Vic Climber) or combined with a smaller, easier to carry small sized blade (like the Vic Classic).
IMO, if you want to have both scissors and a can opener, you'll end up with the fairly thick Vic Climber, or better, the Evolution 14, which has the old superior Wenger style scissor, which have a much more durable spring assembly.
https://www.victorinox.com/us/en/Pr.../Medium-Pocket-Knives/Evolution-14/p/2.3903.E
I find SAKs in this size range to be more "carry in my pack" in size and less "carry in my front pocket" due to their thickness. One I make that move to that form of carry (I carry a day pack with me daily), I just move up to a mid-sized multi-tool. My EDC "carry in my pack" tool is a Leatherman Juice CS4, which adds pliers.
We are in YMMV territory. Main point here is that IMO, the combination of a can opener and scissors will lead you to a fairly thick tool, that may exceed your pocket carry preference. Or not. Only you can decide that.
You mentioned the desire to open packages for your daughter and the ability to drive screws. My kids are now grown but as a dad, I found that package opening and screws often went together. I'll mention 2 tools, both in the mis-labeled "keychain" category. Mid-labeled because they get much more use if carried in the pocket.
Neither tool has a can opener but they are easy to carry, so that's a trade-off.
The first is the Gerber Dime, which is interesting because it has a specialized clam shell blade. It has the advantage of also having pliers. You mentioned that you are on a budget. The Dime can often be found for under $20 so I think it's a pretty good value.
https://www.gerbergear.com/Activity/EVERYDAY/Tools/Dime-Red_31-001040
The other is the Leatherman Micra. It's scissors are more like mini-shop sheers and are robust enough to cut flashing and zip ties. Another thing I like about the Leatherman products is that they finish their screwdriver blades very sharp, so they are less prone to mess up screw heads.
Quick story... My wife needed the battery in her watch replaced 2 nights ago and I was thinking about this thread. The Micra's mini-screwdriver is fine and sharp enough to cleanly remove the small screws from the back of the watch. (They handle eyeglass screws too.) The ability to open the tool full length more like the size of a normal screwdriver made the task easier for me.
The replacement battery came in a super-child resistant clam shell and the Micra's sheers quickly and cleanly cut through that. This would have defeated most knife scissors and taken more care with a knife blade.
Neither the Dime nor Micra will give you food cable knife blades nor can openers. I think the basic trade-off will be how many tools you want and what you want to deal with in terms of bulk in the pocket. It's a highly personal decision.