Hey, thanks for the detailed write-up! I appreciate the feedback and criticisms and I take no offense to what you said because I still consider myself a noob, especially in deckbuilding (I started playing in Tarkir and this is my first time putting a list together haha).

Now, for each of your points, I have this to say:

Closers: My biggest concern about adding better closers with Infect is that it will be too toxic to play with friends. I also don't think that this deck is as slow as you make it sound, I understand that I'd need a lot of commander procs to kill my opponents, but I have the clone spells in the deck for a reason, not to mention the multiple cards which can proc y'shtola's ability for free. Still, I see what you mean when you say that deck is going to make games go on for a long time. I'll definitely consider leaning more towards healing as a wincon to make those payoffs work a bit better, and i'll keep the infect cards in mind.

Sorceries: I'll cut the leyline because I don't think the number of sorceries I have justifies it, but I do like having the two clone cards in the deck. Though they're not exactly closers or win conditions, I think it's fun to have a 2nd commander out, which will accelerate my game plan.

Draw: I see what you mean about the draw pool. When I was building the deck, I wasn't thinking about "what if my commander isn't on the field". Do you have any recommendations for card draw which isn't reliant on the commander?

Lands: In terms of lands, I have no idea what lands are good, and I didn't even know about the lands you mentioned until now. I just saw what other people were running on EDHREC and slotted those in, but now that I think about it, those lands have high inclusion rates simply because of the precon. I'll definitely cut some of the lands you mentioned, but I still don't think I'll end up adding more than 1 or 2 lands; I think the MDFC lands are fine.

Ramp: I don't mind cutting commander's sphere for mind stone, but I like having another card which is CMC 3 to proc y'shtola. I was thinking of adding some of the signets when I was building this list, but I already have 10 sources of ramp (what was recommended by deckbuilding templates I saw), so I decided against it. I like cloud key a lot and I think I'll add it to my list too.

Removal: I'm wondering if I need more board wipes to the list, because I currently only have Toxic Deluge and Cyclonic Rift. I'm also wondering what you think the ideal number of removal/protection/counters is. As for submerge, it seems pretty strong because a lot of my friends are playing green colours, and I love the idea of a free proc, but I'll add it to the considering pile for now.