I see a 5 min re-enter time leading to the following:

Promote Solo Play: Players get bored of easy stuff, try to solo dungeons as a challenge, with short reenter time and no enterance payment, its a win-win. Players not wiling to wait to form a proper party but just grab random bodies and zombie through it, again, 5 min recast and no payment, you fail, you all exit and try again, skilless stay skilless.

Get everything as soon as possible: Even if its a low drop rate, repeat at this rate you can pretty much get drops fast and forget about this 4-month-to-make content. Getting all classes to 50 accomplishes nothing atm, not much to do in game but look at forums for update.

Making it more convenience/easy =/= attract more players (well you might attract those that stay for couple of months, get everything, get bored and leave)