Not sure which instance I should post it to
The instances you speak of are actually called "communities". Instances are Lemmy servers that contain them. So lemmy.world is a instance, while !techsupport@lemmy.world is a community in the lemmy.world instance.
The desktop you suggested seem to be more than enough for very basic usage (browsing, presenting etc.). I do suggest installing Linux on them, unless you need to use Windows specific apps.
yeah, but this bot is not for the convenience of others.
Fortunately, my idea of this bot has massively changed a few months ago and now I switched from premade "protections" like these to allowing the users of the bot to implement them using Lua.