I'm sorry I could swear I found the answer to these questions a while back but now I can't.
A couple questions if I may... :

1). I believe I read somewhere that there's a cap on buildings(?), is true for research as well?

2). Is there a cap for the # of ships you can have (for a single planet or entire empire)?

3). If there are caps what are they, if I may ask?

The only caps are:

1. The number of planets you can have
2. The number of fields on a planet (can be increased with Terraformers)

Everything else is pretty much limitless, though some types of research become useless after a certain level.

Ahhhh... Cool. So really there is no limit then huh, as long as you have the resources? (Extra planets can basically be "bought" with Rubies, right?)

Kinda (sorta, not really though) another part to the cap question in regards to the "ship-speed-upgrades"....

So, the more you invest the ship(s) main transport method (combustion, impulse, or hyperspace techs.) the faster those types of ships will go for their speeds right?

Or should you stop production in the speed techs as soon as all ships are made (a.k.a. A ship speed max/cap) ?

Gou can get other planets buy building a colony ship.

Look in your technology page. It will show you everything you can unlock, and the requirements, as well as details on what they do.

Ummmm.....Huh, say what?

In your menu on the left, (or in the menu screen if you play on your phone) look for where it says "technologies". Click on it, and you can look at everything in the game: Buildings, researches, ships, and defenses. If you look under the ship section, there is a colony ship. When you click on the name, it will show you all the details about the ship. You do not need to buy your planets, you just simply build a colony ship, and send it to the coordinates of your choice in the galaxy menu.

Ahhhh.... thanks!

ok there is no speed cap level up engines and you will move faster and you are alloud 10 planits and if you use rubies you can get 1 more so max 11 and for all your upgrades ect slick the technology tab while ingame it explains what you need to build to get whatever

Ahhhh.... even better! thank you!