Your welcome. Yes the dados and rabbets are impossible with a jig saw. However, I have been thinking of your situation. They do have smaller circular saws that may work for you. They would be easier to manage in the beginning and later would be very handy to have. Maybe 4 1/2” blade. Some are cordless. I think the trick would be getting a good quality blade. Blades always make the difference. I think you could very carefully nibble out the rabbet with the saw and a good straight edge.