A couple of questions to a couple of problems

[Azera]

Well, I recently just started using the Galaxy Editor and I do have a couple of questions ( relatively simple ) to ask.

1) If I were to create a custom unit, let's say a Battlecruiser, except, I changed the Model of it to the Loki's and increased the cost of it to 1000 minerals & 1000 gas. How were I to make it so that this custom unit can be spawned from a Command Centre?

(Or maybe an Uberlisk from the Hatchery. ProzaicMuze's tutorial to make an Uberlisk : http://forums.sc2mapster.com/resources/tutorials/4284-data-working-with-hosting-and-site-operations-the-uberlisk/)

2) I don't know how to phrase this question, but I shall try. When you load a map, let' say, for example, Phantom Mode. When the game is loading, there is this screen with the tips, and loading bar and sometimes instructions on how to play the game.
How am I to go about customizing the loading screen? I want to be able to make a shoutout to my friends while my map is loading.

TL;DR version:
1) How to make custom units spawn from Command Centres, Nexxi, or Hatcheries (Depends on race)

2) How do I customize the loading screen of a map(where the loading bar is)

And in advance, a very big THANK YOU for your help!

 

[Darkness-4ever]

1. To change the units that can be trained from a building, you have to find the buildings Train ability and add in you're custom unit and set the cost of it in the Info+ field of the ability, as well as create the command card button for the new trainable unit.

2. Under Map -> Map Loading Screen you can change what is displayed while the map is loading.