The PSU is Just Dangerous also Limitinger yourself to such an old Platform isn't a good Idea. In My opinion the RX 550 2gb would be better because the RX 550 doesn't really benifit from 4gb
I would Go with Something similar to this https://pcpartpicker.com/list/CQgDZR
I Like the portability of a Laptop and Usingen My Computer everywhere is Vera nice to have, but i also Like the Upgradeability of Desktops More. Are there any solutions to build a custom laptop?