Top three must absurd fanon ships in Star Wars:  

I came up with my own Tie fighter variant you could use for your #2 spot. I called it the Tie/RG nicknamed the Rebel Grinder and I wanted to come up with my own Tie Fighter inspired by EC Henry's Tie Vector. After I messing around with a few ideas I felt pretty happy with it as it was a heavy armored Tie Fighter capable of doing lots of damage. Later on I thought about it and realized its an absurd design because the Empire already had a better design that does the job and that's the Tie Defender. I was too distracted by coming up with a design for the Empire that I didn't think of a design that the Empire could have actually used.

(most of these are really not that crazy and I do like parts of these but I could not really find many bad ships cuz the fans are just that good)

If I were to deploy a fleet I'd deploy thousands, tens of thousands, hundreds of thousands, and so on because it's way smarter that way. Also, watch Legend Of The Galactic Heroes: Die Neue These to see why.

Easiest way to get around the ultra destroyer, trains and elevators with hyper drives installed. I see nothing wrong with that idea lol

4:39 that one was created as a parody (though tbf I don't blame you for not realizing it, some people actually would do something like that, thinking lArGeR = mOrE bAdAsS

I find a lot of fan designs to be overrated. The biggest issues are Mary Sue ships, ships with bad balancing, and ships whose designers don't understand faction doctrine, strategy and tactics. Also, several eras and factions are completely overcrowded with fan designs (basically… the movie eras) while there are almost none for other eras where there would actually be a need for those designs instead of the 128th useless TIE variant or Clone walker. But one reason for that could be that it's too difficult to come up with something new that's not a derivative of a movie design and still fits the Star Wars aesthetic language.