Without examining you, it is impossible to say "how bad it is if you keep putting it off". But when you have a pathology (whether it be structurally based, mobility deficits, or muscular imbalances) and there is associated pain, neurological, or other symptoms present, there is always a risk of increased issues if the problem is not corrected. Now I am not saying that you need to have the surgery to fix the problem. With your shoulder situation, knowing you have the Type 2 acromion and also knowing that the bulk of MMA athletes that I have worked with have overly tight pecs, poor posture, and kyphotic positioning, there is a possibility that your pain is not coming from the SLAP tear, but rather from an impingement occurring due to the combination of the acromion process shape and the tight pecs, etc. You can't change your acromion process shape without surgery, but you can do something about the tight pecs, poor scapular kinesis and positioning, etc.
Again, without a physical exam, I can't tell you if those are your exact issues, so I will again recommend finding a good practitioner who can do a full ortho assessment as well as a movement quality and postural screening to determine where your shortcomings are located.
And here is your original post from earlier last year: http://tnation.T-Nation.com/hub/fightu35#myForums/thread/3862203/0