Re: No cleats on boat. Where to put them?
For lightweight areas consider the nylon (black plastic) cleats and rope guides. They are still pretty strong and don't hurt as much when you kick them. They will crack in freezing weather.
Around salt water, the fewer moving parts, the better. Thus I'd avoid pop-ups and especially spring-loaded ones.
There's an aluminum jon boat called something like G3; my brother in law has one and it had no stern cleats. He needed some for light-weight mooring, so he just screwed them in (ice pick to drill hole; sheet metal screw). Cheap easy and effective.
Since you have the choice about where you put them, consider how exposed and convenient, or not, that you need them; the exposed convenient ones catch stuff. Also rig them based on the projected direction of pull: you don't want a line to pull up against the cleat, directly on the screws; you want lateral stress.
Get cleats with a hole in them so you can keep and extra line in it (such as for a bait bucket or drab line) and you can run the lop for a mooring line through them for quick tie/release. It make s it nice if you don't keep your lines tied off all the time.