Hi Marcus, great post and tips! I think the most important advice I have gotten was to never use an old presentation and simply adapt it but before writing slides, think about what you want this audience to learn from you. So, expanding on your point 3 and Emilia's comment:
Figure out what the main message is you want to get across and substantiate it with 3 arguments. You might have many messages and important points you could but considering you need 2-3 minutes for Intro and context, and 2-3 minutes to present that main message, you have about 3 minutes for each argument supporting that message (can be your results, the model, ...), so there is really not time for more!
I also think that your 2nd point cannot be repeated often enough: Practice the talk, and not just by silently slipping through the slides but with a timer and talking out loud. Rule of thumb: on average you need 1,5 minutes per slide (including the title and thank you slides!), so for 15 minutes 10 is a good starting point.