The tech tree is pretty straight-forward, what you get at the intermediate levels is pretty much what you get at the advanced levels, just bigger, stronger, more expensive. The only critical decision is splitting up your research so your empire is competitive in the short-term.

I'm not sure if the tech tree even has multiple pre-requisites, if you want dreadnaughts all you'd need is Xeno Engineering, Basic Logistics, then choose Advanced Hulls and when it's done don't choose a new thing to research. It'll stay on that track and in a few(hundred) turns you'll have dreadnaughts. It's a similiarly short sequence to get the best lasers, or the best research centers, and so on.

I guess it's true to unlock the pre-made designs you need to get a fairly random assembly of weapon, sensor, defense and engine technologies, but frankly those premade designs aren't worth it. Some things are a little tricky, can't tell you right off the bat what you need to get for Xeno Ethics or to get better Starbase factories, but I'm a pretty casual player it's probably quite simple.

A research queue would be nice though.