"How do you assess comprehension of your main point/content throughout? My problem: I say 'does that make sense?' and with silence I move on."
Couple of things here:
1. Never ask "does that make sense?" The reason is, as an audience member, I don't know how to respond. Do I say yes or no? Do I raise my hand? Do I throw something at you if it doesn't make sense? Etc. If it doesn't make sense and you want me to tell you so you can clarify (which is ultimately what you are looking for), I don't want to raise my hand or let you or my peers know that I'm not understanding something that, if I am the only one raising my hand, everyone else is getting. That is an uncomfortable situation most audience members don't want to be in and will avoid by simply doing nothing (which is why you are getting silence.)
2. So, how do you assess comprehension? Well, it starts with knowing what level of comprehension you need them to have. Google "Blooms Taxomony" to learn more about what I mean by that.
3. After you establish what level of comprehension you want, then you will know if you need to do a little processing or a ton. A strategy I use for comprehension is called SPG. Solo. Pair. Group. After you cover something, give them some time and space to reflect on it. Maybe ask them to take a few extra notes about what you just covered. Then have them pair up with someone and discuss what they learned or ask their partner to paraphrase. Just get them talking to someone in a safe zone (i.e. - not in front of the entire group). This will give them space to validate their internal questions or dialogue. Then the Group is simply asking for comments. Your chances of getting them will increase dramatically by going through the SPG formula.