Hunger is pointless once you've set up a home and everything. There are so many food items that dying from starvation or low health because of starvation seem utterly stupid. Also, I could travel to the edge of the Minecraft map and never run out of food, because I can just slaughter every cow, pig and chicken I see. Pass through a jungle or two and you get melons with ease. Villages have wheat, carrots and potatoes, yet more easy food. It's only ever an issue to new players who don't know how to deal with hunger.
Potions are needlessly hard to acquire but have a nasty habit of screwing up the already iffy Minecraft PvP side of things. Nether fortresses are a nice addition to an otherwise boring Nether but unless you know that they spawn regularly mainly in the Z coordinate, you could spend forever looking and never finding one, and even then you need to hope there's a Blaze Spawner and a nether farm there. PvP in Minecraft was always rather one-sided, whoever has the best enchantments wins, but potions mean you can just spam instant harming II or instant healing II and that's it.
To go off on a tangent, I HATE the MCMMO plugin. On a server with PvP matches in which everyone gets the same equipment, someone with a high MCMMO skill can instantly kill other players, no matter what armour they wear or what enchantments they have on their weapons. Higher ranks also introduce effects that are completely overpowered, like blanking out your entire screen with the nether portal effect for 10 seconds or poisoning you or giving you enchantment effects without the need of enchanting your weapons.