I'm with you. All points were painfully obvious. "Try to find the shortest trip", "Check for a nice departure and arrival time". I mean, really?
I'd add many, many others, for example: don't book priority boarding with ryanair if you're a solo traveller; just get on last (this also means you get to keep your legs stretched as long as possible) and sit between the people at the front who always grab a window and aisle seat. Everyone else then roams further in to do the same, midway down the plane, leaving the middle seat free.
I don't understand what you mean with sit between people in the front. What is the point of that? Is not the middle seat something you want to avoid?
Ryanair flights are packed so tight to the aisle (which sees so much traffic by Ryanair's cart-pushing peddlers) that aisle seats are simply a guarantee of getting your shoulders or feet barged, not extra comfort. Fool's gold. The benefits to sitting at the front (besides not having to get on til you absolutely have to) are hassle-free and speedy embarking and disembarking, beating the rush to passport control/immigration desks.
The biggest tip I would add on: just because an airport is named for a city, doesn't mean it is close. For example budget airlines in Europe often pick really shit airports, such as London Stansted, or there's an Oslo airport that is ~90 minutes away from Oslo. Even for decent airports, depending on your final destination, there could be a big upside/downside chosing between London Heathrow or London Gatwick... New York JFK or Newark..