Players have previously expressed interest in a Survival mode, and although Factions would certainly fulfill most of what one would be looking for in Survival, there may be worth it to consider adding a separate mode later.
I haven't noticed demand for a "Prison"-type server, as defined by endless mines and leveling up in order to eventually be set free(?), but this too may be fruitful to consider.
Lastly, I would suggest a different kind of Prison - a prison escape. Players would be divided into two roles; prisoners and cops/wardens, of which one would have to purchase cop/warden separately. The gist of the mode would be to escape the prison without being killed (and thereby sent back) by the present cops and wardens. One would have to survive parkour, traps and mazes, all while hunted, in order to successfully escape and thereby earn some amount of money. The money would in turn be used to purchase weapons and armour, potions, enderpearls, et cetera, from a prisoner-shop.
The mode would consist of many cells surrounding a central common area, overlooked by a wardens' office accessable only by flying (which would perhaps be a privilige granted to warden). A cafeteria, PvP arena and of course the beginning of the escape-route would be adjoined to it.
Prisoners would be able to form gangs, and thereby compete against each other, as well as the cops and wardens hindering their escape.
Maybe mining and lumbering could be an alternative (albeit less profitable) way of getting money, but that may take away from the actual prison-mode, so I can't be too sure about that.
You show promise, both with regards to your eagerness and greater than required age, however I regret to inform you that it is a requirement to have at least one day of activity on the server before applying for any position. Please join us and play in order to get to know it, and us, before applying again.