Yo, welcome to the forums and this great game. Glad you're enjoying it. To answer yer questions, lad:
1) Colonies grow depending on the number and quantity of normal and luxury resources that they receive. So you need both a source of luxury resources(you can see which in the expansion planner and the sources for it) and a large quantity of it(again the expansion planner provides that info). The quantity greatly depends on the distance from and number of sources, and, more important, of spaceports. Because a spaceport, even a small one, greatly increases a colony's ability to receive and supply cargo, especially from foreign trade( yes, once you have a trade agreement, your colonies get the stuff they need and you don't have from the other empire). So, try building at least a small spaceport per system and increasing the number of luxury resource sources and you'll see a boom in colony development in a couple of years.
2. Yes, culture rating is actually development level, and in turn development level depends greatly on luxury resources, the status of 'capital' and the ruins currently on the planet. If you have lots of luxury resources a planet can reach 90-100 culture rating rather quickly.
3. The Loros fruit is an EXTREMELY valuable resource and you should hold on to it tightly. It is required by all your colonies and so all of them should receive it, provided you have a well developed trade network. Trade network = spaceport network, basically the dotted lines between systems, which mean that resources flow between the ends of those lines. All the systems connected to the system with the Loros fruit get the resource directly, the others get it from the first batch of systems and so on. So if you have a good network of spaceports, cargo will move very fast between worlds and all of your colonies will get it.
The Loros fruit gives a great development bonus to colonies and a population boom, as well as morale. It's advisable to build a proper mining facility for it, or if it's at a colony, you need a big spaceport, because a HUGE number of ships will come to get it.
I have written a few tips and explanations on developing a trade network here, if you're interested
As for the korrabian spice, it's also a great resource for your colonies, granting huge development bonuses. You should try to set up a trade agreement with the other empire so you get more of that. I recommend you trade your loros fruit with that empire as well, that way both of you profit. As with the fruit, all of your colonies should get the spice, but it depends on your trade network. To ensure that you get the maximum amount of spice from trade you should build a medium or large spaceport as close as you can to the other empire without entering their borders. That will make trading a lot more easier, especially if you have a trade agreement, and tons of freighters will come at your spaceport.
To check if your colonies have a resource, open the build menu and click on cargo, it should show all the cargo on the colony.
4. Well, if you build it in an area that says 'black hole name' in the corner of the screen when you look at it(meaning you are looking at the area of the general phenomenon) then it should be ok. I recommend adding a few labs of each kind to the resort base design for an extra bonus.
Hope this helps
< Message edited by Merker -- 11/13/2010 7:40:54 PM >