First Playthrough SMG/Grenades build?

[Kpop]

Preface: I've played a few rpgs like this in my lifetime such as the OG fallouts so I'm not entirely green to the genre but I'd definitely like some pointers to making an effective build.

I've looked around but I couldn't find anything more than a few threads that had up-to-date information. Some gave me a few ideas but not quite what I was looking for. That said, what I've gathered is that I think I would want to start with something like this...

http://underrail.info.tm/build/?AQMKBQgDAwgPCgAAAAAADw8KAA8ADwoAAAAADwAAMQg

Not sure what my endgame would look like build wise. Extra constitution and increased critical rate never hurt anybody is what I'm thinking. I've heard earlygame ammo can be scarce so investing up to about 50 effective pickpocket skill would do me well, but if it would lock me out of getting some nice things later I would probably skip it and just try to get by in another way.

I'd definitely pick up suppressive fire and then opportunist for when I level up a bit more though.

Questions I have:

-Is expertise worth it? If it's flat damage applied on attacks(which in theory sounds good for multi hit attacks like bursts from SMGs) will critical damage scale off the extra damage? Or am I just wrong thinking that stacking crit is the way to go?

-Breakpoints for certain skills: I know you need mechanics to craft nice weapon related stuff, chemistry for good grenades, biology for d R u G s. What should I take these to?

-Other skills: I don't know if I would need some investment in stealth or not, same for tailoring to craft some nice stuff even if I don't take it at the start. Are they necessary and what would be a decent stopping point?

-Dodge and evasion: In other games I've known dodge to negate damage and effects from a direct attack and evasion to be for avoiding area of effect damage. That said, I don't know what they do in this game. How important are they, if at all?

[Sat]

Before getting to your questions, some remarks that may be helpful.
I would slightly change some starting stats.
Decrease Int to 6 so you can raise your Con to 9 to choose Survival Instinct (Otherwise, there is no point to go that high on Con) and raise Agi to 6 for Spec Ops that is a pretty good feat.

With 3 per, it would be wise to take versatility and max melee. It will be more accurate and damaging. There is no point to go higher on Guns than 50 (or other amount depending on other feat you select).

You may go through to a topic called Stormtrooper, it is about energy pistol but it will give you some insights on versatility and max dex for Guns user.

About your questions:
- Expertise may be valid at level 10+ but is not applied on critics. If your critics chance will be above 70%, expertise is not very useful. It is better to choose Critical Power and craft relevant Smgs.
- You would need all crafting skills at good level, 80-90 points shall be enough in Tailoring, Electronics 100+, mechanics at 90-100. Chemistry at 75+, you must be able to craft your grenades, precise amount will depend on your biology skill.
- You can invest 50-70 points in stealth with equipment you will be sneaky.
- Dodge and evasion especially the latter are nice but you could live without if you struggle with points. It is either all or nothing. The best defense is not get shot. for that, you have traps (25 points for quick Tinkering are far enough). Persuasion is not a must amd I would trade it for mercantile that is super useful.