I don’t have the insight table, but I do have a Sweet 16, so I can answer a few of your questions. You don’t need a knee lift with this machine because the hopping foot is controlled by a button on the control panel. I default to needle down, and only raise it when starting or stopping. As for rulers, I love the Line-Tamer ruler for SID and other straight lines. I also really like the HQ Versa-Tool ruler. I would recommend you not get a bunch of rulers at first. Buy them as you want for a specific quilt. For example, I don’t like clam shells, but I sadly have two clam shell rulers. I do love long wavy lines so I have three rulers for those with varying depths and curves. I got one from a friend who doesn’t like wavy lines!
I don’t have a stitch regulator because
1. It wasn’t available when I bought mine and
2. I am forgiving of myself for not having perfect stitching.
I might have bought the table if it had been available originally, but the upgrade cost is more than I am willing to spend. No matter what you decide, find a dealer or show with the machine on the table and try it first. Plan on spending at least 30-45 minutes with it. Being a few scrap quilt sandwiches and make them let you practice with a ruler or two.