This was my project to test out using the serger for a whole garment. So I used the serger and only the serger for all the seams. I'm still not quite sure if this is "proper" with a basic 4-thread serger like mine (no 'safety stitch' or even 'mock safety stitch'), couldn't seem to get a straight answer from my web research. But anyway, I'm sure it will hold up to my use and I see it or something similar done in factory-made garments. I am very happy with my used serger purchase, got a janome 334. And it was much simpler to get it threaded and figured out and get serging than I thought.
I bought this men's XL shirt from a thrift store because it was lovely and soft and I loved the pattern. And since the sleeves were too short for Kev (look how short they are, I couldn't even get full length sleeves for me after cutting off the cuff), I cut it up and used the material to make a cozy casual shirt for me. Did a mandarin type collar again - just think that looks cooler than a regular round neck.