Volt

It's an otome game so probably not what you're looking for exactly but Collar x Malice's heroine, Ichika, drinks in pretty much every route. 

Welcome to Fuwanovel, and feel free to ask more VNs recommendations if you need more. Sorry for the belated greeting, and I hope that you'll have fun here.

I would say that if you have less time then you should chose G-Senjou, because you'll only need one VN to finish everything. While for Grisaia, well it have two more sequel (Or rather fandiscs) that you may want to read if you want everything concluded satisfyingly. So yeah you should try G-Senjou if you just want a shorter mystery VN. Either way I hope you'll have fun with your husband there. Also Shibuya Scramble here is a mystery VN with a lot of still photo that involving the player to piecing the scenes, so you may pick that up later if you've been interested with it.

Out of all of them I'd recommend Grisaia as your first choice, especially if you want humor as the common route may be long but it is very funny (especially Michiru's antics). Not very many choices in that one though aside from what route you go on (just don't play Yumiko and Makina's route back to back). As for the second one I'd recommend either G Senjou no Maou or Muv Luv; the former if you want some humor to go along with a bit of a thriller and also want the added bonus of the main antagonist being voiced by a before he was famous Jun Fukuyama, ironically doing what feels like a take on the later role that would make him famous , and with the latter if you want a slice of life comedy.

428 is only 10€ right now (instead of 50€) and it's one of the best VNs on Steam.
As for your wishlist, each of the VNs (except maybe Maitetsu, which I haven't read) has some aspects you might consider "long-winded". Grisaia has a very long common route (~40 hours) without an actual plot. G-Senjou no Maou has rather mediocre side routes (which you can skip without missing anything though). Baldr Sky is really long and has a section around the halfway point where you have to re-read several hours of content you already know. Muv Luv takes until the third game to actually get good. And Root Double has a habit of overexplaining its plot points and devices.

i dont want to make you confused for another title, because there so many good VN.
if about little busters there have same plot or story but will some bonus about other routes, so ill try picking new first. So I would recommend from your list, ill pick G-Senjou no Maou first, if there next then Grisaia. the reason is, if you take griasia first, you will be hooked to playing  the same saries ex: rakuen, meikyu and etc
so pick g-senjou no maou first, both are so damn good

For a VN with no enforced route order I'm in favor of putting in either an equal amount of plot reveals for every heroine or the most of plot reveals for the main heroine, because the main heroine route would end up feeling less significant when you add the least amount of plot reveals.
Though, I am generally in favor of enforcing a certain play order, especially the type where you need to play a certain amount of side routes before going into the main route. One of my favorite VNs does this pretty well in my opinion. It's an otome game though, Collar x Malice. The game has 5 love interests out of which you can only pick 3 in the beginning. Once you finished one playthrough the 4th one becomes available (because vital plot points are revealed in his route) and once you finished all other routes you can finally unlock the main hero/true route where the main mystery will be revealed.
For very story-driven VNs I guess it's easier for the writer to lock certain routes, because you don't have to keep in mind all the details along with a mixed playthrough of routes (it's difficult to keep track of everything that way and for everything to still make sense with a complicated story) and instead slowly build up suspense by adding layer upon layer with each route you finish and unlocking the next one. Just like Clephas pointed out, it builds up anticipation for the reader - with the downside being that it needs to be better than the side routes or the reader will be let down.

well if not unlockable route i did the bonus or side characters first, then go to main heroin. OFC ill put the cutest personality in the last. If i do the main for first when there sideheroin ill maybe skip the main heroin to cuz lazy to go the same plot's

Newbies tend to play the heroine they like the most (often the main heroine, since they are often written to attract the reader's interest) first.  Vets almost always play the main/central/true heroine last.  
From a maker's perspective, they want the readers to play through all the paths, so locking the main/true heroine path makes perfect sense.  From a reader's perspective, a locked path means anticipation of what might be revealed.  

One thing i noticed is that while some VNs have main/cover heroine routes with the assumption that they are gonna be played first (Rewrite and original MajiKoi are what comes up off the top of my head), a lot of people in the VN community seem to prefer doing the main heroine route last.
With that in mind, i ask: when it comes to main heroine routes on VNs with no enforced route order, is it smarter on the writer's part to put the least amount of plot reveals (assuming it's gonna be played first) or the most amount of plot reveals (assuming it's gonna be played last)?

Welcome to Fuwa! And well, I hope you'll enjoy the massive choice of things to read, having too many quality titles to choose from is a problem VN fans of the past wanted to have.

yo yo yo!

welcome bruh, there is no late for reading VN, just enjoy it

welcome. make friends and such   

Thanks for the warm welcome, everyone!
I will most definitely enjoy the huge amount of quality titles available. I remember back when I was reading Ever 17, there wasn't even a fraction of titles coming out compared to now.