Well let me clarify some things. I am decently familiar with the 'Dota 2 But <...>' scene so I think I can bring something to the discussion.
First of all, it is horribly organized in the Dota 2 custom maps section, littering the map browser. I urge you most importantly not to copy that, as it only leads to disorder in maintaining and updating the maps. Not mentioning that these maps will eventually be scattered all over the section, and without each other, these modifications are more like quirks, they are not full.
One has to be inspired by Dota very cautiously. Since it is a step down from the original game (Starcraft 1 and Warcraft 3), some of it's elements better not be brought back. The standards are also awfully low there.
And I'm not talking about the idea itself, just the implementation and organization practices.
For example, 1-hour Stormbolt or a health/mana swap are not meaningful changes in Warcraft. In Dota it mixes up the whole balance/game flow since it only consists of heroes with health and mana.
Since all non-spellcasters have no mana, the only solution that would make the game playable is to make them have 1 health.
Honestly I don't think that the majority of units having 1hp is exactly playable.
As a good reference, on the other hand, you can look up Starcraft 2's "Imba League" map (youtube: Husky). In short, it allows to select all the desired modifications at the start of the game (can be done with dialog/UI/dummy abilities). See? Already much better than what 'Dota 2 Buts' offer and it existed years before.
To my ignorance, I haven't heard of much similar maps done in Warcraft, so i'm really looking forward to what
you will make of this idea!
As a heads-up I can give you a couple of ideas just for the sake of example:
1. All units and heroes have Pillage
2. All units have Blink; 400/700/1000 range for tier 1/2/3 units
3. All buildings have a ranged attack; ranging from Archer-level (Farm) to Gryphon/Frost Wyrm-level (Castle)
4. All modifications are in one map. <3 Take something classic like Twisted Meadows, or some bigger 8+ player map, whichever you think is best suited to be the template for your gameplay modifications.
It doesn't really matter if you miss a mark, as long as you work diligently towards a goal. If you're still interested in it, that is!
If you have any questions, you can contact me at discord MadSkills#0057 or join the Hive discord server. There are many experienced people who will surely help you with the technical details.
Good luck with the development!