Yeah, you definitely need action surge if you're building a first round ranged nova character. I'm assuming [MENTION=6795602]FrogReaver[/MENTION] was still optimizing that 1st attack, rather than the first turn, when he said you didn't need fighter. Though even then, you really don't want to miss, so if using sharpshooter, the +2 to hit from archery style is valuable also even with advantage. Wood elf would probably be my choice of race for the darkvision, access to elven accuracy, and mask of the wild, which I think probably outweighs the extra feat on balance, unless you are planning on Gloomstalker relatively early and planning for Skulker at some point, which make most of the wood elf's racial abilities redundant.
It sounds like [MENTION=6993955]Fenris-77[/MENTION] and I agree about the first 10 levels being Assassin 4 / Fighter 6, though I might rather go Rogue 4 right off the bat, then take fighter levels after that. You get your key ASIs a lot sooner that way (4, 8 and 10, instead of 7, 9 and 10), get your assassin identity online as soon as possible, and get an extra skill proficiency, which is nice. The CON saves from fighter aren't that critical since you're not making concentration saves, and action surge is worth more once you have some feat support behind it. But either way.
After that, let's compare Gloomstalker vs additional rogue levels. Ranger 1 is a dead level, which is rough, so you'd definitely rather have Rogue 5. Ranger 2 gets you Hunter's Mark, which is better than having Rogue 5 and 6, unless your bonus action is spoken for (but it probably isn't unless you've taken Crossbow Expert by then: if they're surprised you're hidden already, so you don't need to hide again; and if they're not surprised and you're not hidden, you get advantage anyway as long as you beat them in initiative). Then Ranger (Gloomstalker) 3 gives you another 1d8 plus additional hide-ability and initiative. Between Hunter's Mark and Dread Ambusher, when combined with action surge, you get more damage in that first round than crossbow expert (used with -5/+10) gives you (of course after that first round, crossbow expert is better). And of course, you can get the next ASI/feat at 14th level just as you would if you took more rogue levels. It's not until 16th that you're down. But even then, factoring in the initiative and invisibility to darkvision, and the ranger levels are probably worth it even if you never get crossbow expert. But that's from a perspective of aggressively optimizing that first round; the rogue levels and the feat have lots of other nice things that may well be worth more from the point of view of having a well rounded character.