Hey,
first of all, it's nice to see that you have grouped up your deck. this helps alot for review.
Do you really need
Acidic Slime? with cmc 5 and usable only on sorcery speed, he's a bad removal. alternatives (in addition to those you've already added) would be
Viridian Zealot,
Knight of Autumn or
Elvish Scrapper. If you don't want to stick to a creature,
Return to Nature or
Nature's Claim would be great alternatives.
Then, your land base. My golden Rule for lands is "If it always enters tapped, it needs to have a significant effect.". Every land that enters tapped slows you down by 1 turn (especially early on) and you basical pay 1 mana for the effect since you can't use it. With 15 cards for mana ramp/fixing, the colorfixing shouldn't be a problem. A little more Forests than you need according to your colorpie are useful here, to make sure you're able to play your mana donks.
Besides that,
Fellwar Stone and
Exotic Orchard do a suprisingly good job for colorfixing in 3+ color edh decks. Since you're playing multiplayer, the chances are good that you'll find your colors elsewhere on the table.
A special notice to
Bojuka Bog: I don't like this land. It enters tapped and, at least for me, there was very rare cases where I was able to play it when I need it. Usually I plaed it before I need it, because I needed the mana.
Good alternatives for Graveyardhate that would fit into your deck are
Tormod's Crypt,
Crook of Condemnation,
Deadeye Tracker,
Heap Doll,
Nihil Spellbomb and
Watchers of the Dead. Especially for graveyardhate I prefere stuff on instant speed, because this allows you to break alot of moves/combos that would cause alot of trouble otherwise. Especially with your commander you should know what I mean.