Yes, I'd at least look into getting your old Dremel fixed. The current ones have plastic cases, and last time I looked on Amazon, a lot of people were unhappy with the quality.
If you can get time, you should do some research into desktop lathes and mills; last time I checked, there were plenty of internet resources, and the Chinese ones are relatively affordable (<$500-$1000). Of course, they have limited sizes, but a full size one does take up a lot of space.
Also, could you use a scroll saw for making holes? Another possibility is electric cutout tools.
Since I've used hand nibblers, I like the electric version; another option might be body saws ("designed for cutton car bodies and other metals").
@TonyTib... "I've been mostly buying corded tools.....My current rotary tools is a $20 Harbor Freight variable speed..." In my experience you can get a decent corded drill a lot lower down in the market range than a cordless drill. A decent Cordless drill will be expensive. but in view of your info about Dremel it might be worth my while to get my old (and I think good quality) Dremel tool fixed.
Milling machines...and lathes....good point. I have had 2 or 3 friends who have owned both (handy guys to know) and while I would love to have these tools I can't warrant the expense for the amount I would use them. They are like Microcontrollers - you are limited in what you can do with them only by your imagination.
Since I don't tend to use power tools a lot, I've been mostly buying corded tools: they give lots of power without having to worry about charging the battery or paying for Lithium batteries.
Dremel is now owned by Bosch, and I'm pretty sure all the Dremels have been made in Mexico for a while. My current rotary tools is a $20 Harbor Freight variable speed; it's decent quality, but is kind of big. If I wanted something expensive, I'd get a Proxxon; they're not a whole lot more than Dremels, they're made in Germany, and a friend who does woodworking says they're a lot nicer.
BTW, another way to make holes is to use a milling machine.
Hmmm...interesting...I like the set in first link in your post, but I can see that swivel arrangement in your third link would not be too robust. The thing I was thinking of is like the below - sorry I could not get the pic to post, just the link.. The drill has 2 chucks on a pivot and you turn the whole head to put one of the chucks in the driving position. Google "dual-drill" and you can get some videos. I have not heard any reports of this - good or bad - but it looks pretty handy. I was recently putting up screen mounts for a video conference installation and was successively drilling a hole and screwing in a holding screw - this would have been really handy.
I have also seen cordless drills with two chucks that you can swap between by swivelling them round. This is very handy if you want to drill and then drive screws in quick succession because it saves having to swap back and forth between a drill and a screwdriver bit
I am not sure if you are referring to sets like this one or this . They often go together. In the former you can interchange drill bits, screwdriver bits or nut drivers by pulling on the collar of the knurled thing you see on the top right hand side, replacing the bit and ressetting the collar. It is great for quick interchanges even if you have a drill machine with a Jacobs chuck (which most do today).
In the latter this goes one step further bwhere you mount the drill bit on one side and the screwdriver on t'other which you see on the second device from the top. It mounts in the contraption above it and can be pulled out and re-inserted in the opposite direction allowing you to drill a few holes then insert the screws rather conveniently.
There is a third variation where this drill/driver combination is mounted on a pivot so the flipping action is even easier. However, the ones that I used (not the one here) was not quite as robust as I had hoped and I went through 3 of them building my deck. I don't know where the set is now, I thimnk my son has it or I could get a better picture.