The warnings and caution around routers (and by extension, band saws and table saws) are meant to give you a foundation for safety, not to scare you off. These tools are meant to rend through wood. Our flesh is much softer and squishier.
That being said, I started with an old Porter & Cable that I inherited from my in-laws, a model built when "safety standards" were "a nifty idea." I even posted about that on this forum a few years ago.
I had a healthy fear when I laid it into a scrap piece just to get the feel for it, and I was not disappointed. It can be terrifying, but with a good, clean cut, the results are also highly satisfying. I've routed countless times now, but I do not and will not lose my respect for them, and I still learn every single time I use them.
I've retired the inherited router now, and replaced it with three newer models. Two are full-sized corded beasts, one is a battery powered one. The two full-sized are a Bosch which resides permanently in my bench-top router table, the other is a Skil that I use for heavy duty, top-down work like the control cavity or trem spring cavity. Both accommodate the ¼" and ½" shank bits. The battery-powered one is a smaller Ryobi which I use for more precision work like neck pockets and pickup cavities, and that only takes the ¼" bits.
I've found that, compared to a true router, a Dremel is too vastly underpowered to be effective at the larger work like bodies and cavities. Maybe good for inlay work, binding channels, and other smaller, precision areas, but I wouldn't waste my time or my Dremel's motor on trying to cut out a whole guitar body with it.
The templates in your post are the same ones I use, from GitrBuilder on eBay. I have quite a collection of his products

I suggest, as part of router practice before laying a bit to a real stock piece like those pretty blanks, is to make copies of those templates on sheets of MDF. MDF won't kick back or be subject to tear-out like real wood will, and if there's anything that's a confidence killer in your beginning stages of routing, it's tear-out.
And that'll also save your original templates in case of accidents or just use over time. I've used my Tele template so much but didn't make a copy of it that it's wearing out. Plus I also misjudged bit depth once when using it to route the control cavity that the collet on the router came into contact with the template itself and started burning a channel through it.
(another learning experience)
All in all, routing is like driving a performance car. It takes greater expertise, care, and caution and with just a fraction of a second of carelessness, potentially deadly, but it's also very rewarding.
The other safety aspects of routing is, in addition to goggles, wear a respirator and hearing protection. A good quality respirator is essential, especially if you're going to rout MDF. Those microscopic particles are brutal on lungs.
Finally, don't skimp out on the tool itself. I avoid Harbor Freight like a plague with anything beyond the simplest of simple hand tools. They're all cheap for a reason. While I'm not saying you should go overboard and buy a router from StewMac for $5,000 (they don't sell routers, but they would if they could

). Mid-grade major-name models have better quality than anything available from HF.
Same with the bits. It's tempting to buy those off-brand el cheapos from Amazon, but again, you get what you pay for. Out of necessity one day, I went to the hardware store in the village where my cottage/workshop is because I needed a replacement router bit. It was some no-name off-brand. It was utter garbage. I could feel the difference as soon as I fed my workpiece into it, compared to the Freud or Amana bits I normally buy. And I could also feel and see how bad the cuts were.
Don't give up on this. Just temper your expectations and the expected rate of your progress. While you say you want to commit to your first, last, and only router, as you'll note in my own tale, that's not always realistic. Again, I have three, and each of them have very specific uses. You may or may not find yourself in the same boat.
Just as playing music isn't a cheap hobby, neither is making the instruments we play. Shortcuts only lead to disappointment and sometimes, the tradeoff in saving a couple of bucks up front versus what you get in the end may not always be favorable.