Painting textures in Maya is really not that difficult and painful as some saying.
You can easily create seamless textures with Paint Effects. But there are some limitations (you think).
One limit is the resolution. (2048 px maximum.)
Well it is not. 🙂
Find this file:
Open it with a text editor.
At line: 831 and 832 change the two values form 2048 to 4096.
int $kMaxSizeX = 4096;
int $kMaxSizeY = 4096;
Also set the resolution at line 1029 and 1030.
After that, you can use the Set Size command as well to create larger textures.
Save the file.
P.S. You can activate the Paint Effects Canvas by choosing in the Viewport: