Okay, I will post this not directed to you Darkstar, but to everyone in general who is "worried" about this whole thing.
First: No matter how much SP will be reduced for linking and the mobs in general...to even assume it could be less SP than running the leve solo is just stupid. Sorry...with the outmost respect, you are stupid. I think SE is aware of giving solo players more SP than running a leve as a group is just stupid, so they won't do it, that much I don't have to speculate, that much should be fact using common sense.
Second: Bonus for the completion of the leve is based on "performance". Meaning your difficulty setting, your competion time and maybe more factors will add to that bonus. A player doing a leve solo might be able to kill the mobs without much hassle, if they are up to 5-6 ranks above him. Well your SP will be uncapped for those mobs for 4 ranks already...so the completion bonus must be pretty low. A group of people can kill SP capped mobs up to 12-15 ranks above them(even though the mob being more than 10 ranks above you won't give more SP for killing), but it will influence your bonus on completion. So that alone ensures that solo players won't get more SP than a group of people doing the same leve.
Third: Does anybody really believe Guild marks being restricted to cities where the guild is in will change ANYTHING about the habit how people do leves? First, most people give a crap about guild marks on battle classes anyway...second...if they really care about guild marks, they can run some leves solo that reward guild marks which brings me to fourth...
Fourth: Players will ALWAYS do what's considered the best/fastest way of grinding. All other factors are gonna be ignored. If doing leves as a whole is not gonna be the fastest way of grinding anymore after the patch, everyone will switch to the new fastest way of grinding. One fact is, doing leves solo will never be more worthwhile than doing them as a group, cause it makes no sense and I trust SE that much to know that.
If leves will not be the fastest way of grinding anymore but stuff like raptor grinds will be the new way of grinding, lpayers will find camps all around the world to party and grind on...just like it was at the beginning of the game on Crab/Eft/Hog/Raptor grinds.
And honestly...I would prefer party play getting away from leves and more to actual grinding in the outskirts of Eorzea...leves should be a way for people who don't have much time on their hand to still get some progress(which was the initial reason for them) and not the center of everything and I'm glad they will get rid of leves being the center for everything. If leves still gonna be the best way to grind, I can live with that but at least the reduced SP for groups will make grinding on regular mobs around the world more viable.