Thanks Scottr for chiming in here.
If your cuts are wavy, either you have a dull blade or you don't have enough blade tension. The guide blocks, in my personal opinion, unless they are WAY opened up, are not your problem. I have not reset mine in the entire life of my Ripsaw, many thousands of bd ft of lumber. Yes you will be more apt to run into a little wavy cut when you hit a hard knot, but my experience has been that that only happens when my blade is starting to get dull. A new blade and proper tension will blow through even a hard knot. I have found that it sometimes helps to feed the saw at a slight angle through a knot like you are describing when my blade starts to get dull, and that often helps.
Yes, that guide finger does have to be taken off when milling very wide boards, like 12-14 inches. This is the reason I took it off and use my hand/fingers wrapped around that large black knob for all my milling.
The Ripsaw, like ALL shop type equipment (and I have a shop full so I can speak from experience) takes some tweaking and learning the ropes. Common sense, some trial and error and patience are in order. Tension... as scottr says, use that tension guide on top of the Ripsaw. If you are getting wavy cuts, crank it up half or quarter turn and try again (all other things staying same). It's a mechanical device and does respond in logical manner if you take the time to work through problems step by step. Worse case scenario is either you will break the blade, or I've found more likely you will crank it so hard that you will start to torque the whole Ripsaw frame to the point where the blade won't track correctly. I have done that several times, and that's a definite sign that you have it too tight and need to back off a bit.
Read the manual... then reread the manual and take it a step at a time. You can also call Ripsaw or email them with questions.
Dave, the guide finger on my Ripsaw is curved so part of it sits inside the frame and allows a 14" width of cut. It is made of metal that is about 3/16" thick. I think your saw is about the same design as mine.