Yes, you can do everything you're asking for.
A simple fade out could be something like this:
SetVirtualResolution(800,480)
SetWindowSize(800,480,0)
text = CreateText("Hello world!")
SetTextSize(text,50)
alpha = 255
start_time = GetMilliseconds()
do
current_time = GetMilliseconds()
if current_time - start_time > 10
start_time = current_time
dec alpha
endif
SetTextColorAlpha(text,alpha)
sync()
loop
There's also a "tween" command that can affect the alpha, colour and various other parameters of the text so you might want to look at those as well (I've never used them so haven't given an example here).
As for the pixelated text, the default font used by AppGameKit is really just a placeholder and it's best to load in your own, known as a font image - you can either make your own or find one on the internet. I've attached an example of how this would work in AGK.
In the media folder there are two file: font_001.png and font_001 subimages.txt
font_001.png is the actual image for the font (all the letters are white with a transparent background so you may not see them depending on the software you used to open the file).
font_001 subimages.txt is a text file that tells AppGameKit where all the letters and other characters are on the image. Each row is the character, position of the character in the image and the size of the character. If you look at the first row:
65:0:0:25:36
65 is the ascii code for an uppercase "A"
0:0 is the x:y coordinates of where the top left corner of the character is in the image (accounting for whatever space you want around the character)
25:36 is the width and height of the character in pixels (again accounting for whatever space you want around the character)
I made this font image in paint.NET and the subimage in note pad. You do not have to account for all the letters and characters if you don't intend to use them. If you look down the subimage you see a row that says 97:0:0:25:36. 97 is the ascii code for a lowercase "a" but you'll notice the position and size is exactly the same as for an uppercase "A". In this particular case I had no intention of using lower case letters in the game so there are no lowercase letters in the font image. It just speeds up the time it takes to make the image.
Obviously, the larger the font image, the less pixelated they look and the bigger they can be in the game.
You can load in more than one font image and set different text to different fonts using the SetTextFontImage but you'd have to do this for each individual text item.
