Character Ideas

Elric/Minthe: This idea doesn't seem all too bad and actually very possible, but the circumstances must be very unique. Firstly, as you are already aware, Myth DFs must be won. On top of that, it's possible that some events will make only a specific Myth DF winnable. Basically, as your first character Minthe would be impossible to have. Secondly, as far as I know a Myth DF Weapon isn't actually impossible--if anything, just rare and really unorthodox. The complicated thing about having a Myth DF Weapon would probably be that it is likely to be considered a T6 equipment almost by default, especially considering it gives sentience and a range of abilities to an inanimate object. Overall, I see this character setup to actually be possible, just not for your first character. It's pretty difficult to get exceptions made as it is, and typically you would have to prove your ability to use the power granted to you by exception responsibly. I suppose it is up to you to determine how you could show that. Even then, the chances seem a tad slim.

Duumu: On a literal level, this fruit is direct metagame. That in mind, the chances of its approval are slim as it is. Not to say that it is impossible, but you would have to provide a damn good roleplay sample and skill application just to have it even considered. Otherwise, this would be the type of fruit placed in the Banned Section. I could see it being played fairly, but simply due to the fact that it is metagame, the chances as it is are already slim just by suggestion.

Sol: Assuming what is soaked up is, for the most part, limited to energy and power in their surroundings--taking energy from INPCs and PCs, perhaps even normal NPCs being limited or even impossible--the Suu Suu no Mi seems most plausible. Among the characters you have presented, it would be most easily accepted. Unless you really want the Duumu fruit in comparison to the Suu, I highly recommend you go with it for your first character. Perhaps after showing you can be trusted and responsible with your character and his abilities will the Duumu fruit be more acceptable to the staff, and likewise with the Elric/Minthe idea.