Db structure: take a look at Alternative approach to the Bubble’s recent tutorials for list of things
In short you want to avoid lists so instead of
User having a List of Products
You would make a Product type and add User field to it and then “Search for Products where User is Current User” returns the same list as Current User’s List of Products would have. The difference being is now you’ve avoided weighing the User object down.
For dynamic pages, you definitely want to be tapping into reusable elements, url parameters are perhaps easiest , getting the url path as segments/segmented list has a cleaner look. You might have a yourbubbleapp.io/products page and then yourbubbleapp.io/products?name=Product1
As for the third bullet, getting content to fit, you definitely want to take advantage of the new responsive engine & learn flexbox inside and out. There’s a great game designed to do this (and you’ll learn some css to boot):
And as I post this I realize the topic is almost a year old 