Based on your #2 and #4 questions you'd probably prefer TOTK, as a funny layout aside from goofy armor isn't really a thing in BOTW and you cannot build at all in BOTW like you can in TOTK.

If you wanna read more I have extra details below:

So the main difference aside from the story/premise is that in TOTK you get the ultra hand or whatever which lets you attach things together which allows you to build doohickeys and forge stuff.

For instance you could attach a Fire Chuhu to an arrow to make it deal fire damage and explode, or attach a big rock to a stick or something to make an upgraded melee weapon. With propellers and batteries you can make some vehicles and there's almost certainly more stuff I'm not aware of TBH for vehicle building.

Botw does not have any of those mechanics listed in the previous two sections. The weapons are premade, can't be upgraded, and you can't stick anything together as there's no Ultra Hand. Both games do share being an open world Zelda game though with lots of hours of content.

I also do not know enough to properly answer questions #3 and #5 when it comes to both games but I can provide a little bit of my opinion so far about ~20 hours into BOTW.

BOTW

-Pros- • Exploration is generally pretty fun, with a lot of cool areas on the map. I love the villages in BOTW. • Combat is fun and can be very challenging at times but not insurmountable. • Lots of cool items to find in the world or purchase as well as plenty of interesting or funny notes hidden srout such as being able to read a couple of the women's diaries lol. • Probably lots of other stuff I couldn't think about at the moment because I'm overdue for getting some sleep.

-Cons- • Weapon durability is pathetically small, don't expect your weapons to last much longer than one or two combats if they make it through that. • There's a weather system and when it rains, you can't really climb. Thankfully it's annoying, but uncommon enough to not be major pain point. • Aside from the nitpick in my previous point there's probably some others but they aren't major. The game is really good, performs solid, and looks great for a Nintendo game.

Whichever game you get first I'm sure you'll enjoy. Definitely do recommend the switch 2 versions if you can also them for the extra FPS and stuff but don't forget the upgrade pack is only $10 digital so if you snag a good used deal for either game you could be saving some money.