the ability to quickly and accurately do callouts has been an essential part of a support jedis toolkit to play effectively for a number of years, and now people that are upset about ambushes in open are calling for nerfs.
Wait, but that does not make any sense. There is no way for these people to request such changes. As you said, these are the people that get upset about ambushes. But sense does not help setting up ambushes in any way (apart from a few exceptional cases), you can do ambushes just fine without sense.
In fact, it actually defends from ambushes.
i don't really have the confidence that a nerf to sense would be appropriately compensated for by buffs in other areas
I understand your concern, but with current drains and blaster blocking angles for jedi I don't think sense makes that much of a difference in terms of survivability. It is not used during the attack, when the jedi is defending openly he does not really need sense, and if he is not under fire he can just use it freely, and extremely accurately position-wise (which does not really help him that much most of the time).
So, the only advantage it gives is the ability to accurately predict location of opponents that are quite far away, which, given the range limitations of jedi class and the fact they don't really need to aim makes it useless for any pure mechanical skills.
Let's talk softer skills, like positional awareness and inter-team communication. First of all, with the size of maps MB2 has the jedi can see far enough to be able to know the exact location, the quantity, and the quality (class) of the opponents at any given time. For a team that is connected in Discord, Skype, TeamSpeak, etc (like it is always done in competetive) this gives huge advantage to any defending team on any map. Which leads to constant stalemates and frontal head-to-head bumping, with the exception of the cases when the map is specifically designed to somehow break the opposition (Smuggler). I can't emphasize enough how huge it is.
What does it do for open? Most of your team in open consists of random people, that you do not have on VoIP. And you have little time to type in chat for your callouts with the pretty fast pace of MB2 gameplay, not to mention give accurate details. And lets be completely frank, nobody ever does that anyway, even if they could: most of the time there are like 10 people in the team, 5 of which are jedi, 1 of which is hopefully pushing well, another pushes badly all the time (trying to learn how to do it better), the rest just try to rush in and kill gunners, or duel the same kind of sith from the opposite team - right in front of gunners. Why do we even talk about sense here, how does it help? It won't make that much of a difference.
This leaves only the positional awareness of the jedi himself as a factor for open, and due to the fact you do not regen force while using Sense it is very situational: when not in an active engagement. So, you can basically get a perfect refresh of your positional awareness when it is least important. Why not make it dependant on actual player's skill and positional awareness, then? Especially with the margin of error forceuser's defences and mobility give?
Now, what are the consequences of sense being, say, removed? For both modes: generic open and competetive MB2.
For both of these, positioning in corellation to your team becomes far more important. You do not really want to rush into that corridor alone, who knows what trickster may be hiding behind that box over there. Instead, lets do this thing tactically: go smart and careful, check corners and hidy spots, work with team to properly occupy and take control over the location. In the current live build a jedi can just go in and say "clear". Or just run in in generic Open - the gunners will know from that it is clear. And these minute differences are some of the main building blocks of any good teamwork.
For both of these, environmental awareness of each player as a personal skill becomes suddently more important. You would need to listen to your headphones more closely, to watch the radar better, to watch where any shots and flashes come from and to, to watch your teammates, listen to their callouts... All of that is something you can apply your skill to, as well as combine skill with your teammates, which is the ultimate goal of a good teambased multiplayer game.
For both to some extent, but mostly for competetive, it will change the tactics used by all classes anywhere by a country mile. Suddently, creating an ambush or coming from behind is a valid defence tactic. Splitting up for a diversion, or learing the map to find ways of moving unnoticed becomes helpful and actually important for the attacking team.
For open, a couple of bullshit tactics available for forceusers disappears, like slashing an enemy through a door just as he is about to open it.
The only bad thing I see that will have any actually significant impact is the fact it becomes harder to identify timewasters. But hey, we are a community, right? Just call them out on that shit, so that admins could kick them!