3) Acer hardware is awful - built down to a price and it shows
4) Not sure a Chromebook will run any apps that enable interfacing with a Garmin - all I can say is that doing this on Linux is not a plug/play affair
Chromebooks are massively convenient if you can accept the shortcomings - and I think would certainly take care of most of Butterfly's needs
But young folk should learn to computer. Abstractions away from the business end of technology serve to make things worse[3]
3:Not sure where you get that from? My Acer Chromebook 14 (model CB3-431) is the best physically built computer I have ever had and I've been working on computers since about 1982.
Cost £170 - sleek metal case - been in a backpack through torrential yorkshire rain on my bike. (suitable waterproofing of course).
4: You don't necessarily need an app for everything, and in any case many Chromebooks will now run Android apps. It's true that as far as I know you can't run Basecamp on it but you can of course extract all your gpxs off Basecamp. I do most of my long routes on
http://cycle.travel/ which needs only seconds of online time to produce a route. You can then quickly download the gpx in a format which limits points by just marking turns.
You could then get that into your garmin via a USB lead. Or at least you can with my Etrex 20.
True I then tend to tweak the route by going online on
https://www.gpsies.com but you don't have to.
I prefer to number my points (many don't bother) so I do final editing of the gpx file, numbering points and hacking out superfluous padding using "caret". This works totally offline - no internet needed at all. Then it just gets fed to the garmin via the USB lead.
Butterfly, apart from the user benefits, I would also consider a Chromebook on cost as well. You should be able to try a couple in PC World.
Also worth checking out the Argos ebay shop - they do "grade A" reconditioned units, which as I understand it are just returns from folk who opened the box and thought twice. All are I think fine and come with decent guarantees.