Dummies guide needed - what's wrong?

[DJR]

Is it a problem that the banners are taking so long to load even though they don't seem to be preventing anything else to load at the same time?

Is it a problem that the 'Start Render' isn't until after 2.5 seconds?

4 seconds before DOM content is loaded is very poor, presumably?

I'd greatly appreciate if anyone can give any insight into the below Waterfall View. Is there even anything wrong? Thanks!