Looking for a WooCommerce theme that supports certain core functionality

I’m an absolute total newbie at WordPress and WooCommerce. I prefer themes without big graphics. Minimalist with a category menu on the font page.
I’ve narrowed down my list of favorites to about 10 and the “Gon - Supermarket 3” theme is high on my list. But I can’'t find the options I need. So… I’m here for some advise. The price of the theme is no big issue.

My webshop will be very diverse. Stock changes constantly. Compare it to a virtual flea market, a virtual yard sale.
Likely I have to hire a developer to tweak the shop a bit, but first I want to find a theme that fits my needs best.

A]
SUGGESTIONS
When a customer watches the product page of a flashlight, I want the shop to suggest batteries and chargers.
I’ve seen that most product pages show pictures of other products. That’s like what I’m looking for, but I want full control over what’s displaced.
Or any other way to reach the same goal.

B]
LICENCES
I’ll also be selling sofware licences (all 100% legal BTW).
That should work like this.
The moment the customer pays for a licence, the webshop should send a email containg the licence key and instructions.
I have paid the software company for a list of licence keys. That list somehow needs to be entered in the webshop. And very important, each key may only be sold once! After it’s sold, it has to be deleted or marked as sold to a customer.

I’m just someone with a hobby project. I only have 10 keys (and get more when stock runs out) so in theory I could perhaps create 10 products that are 100% the same except the key connected to it.
But that would look very bad. A shop listing 10 identical products looks broken.

C]
T-SHIRTS
There are a great many fashion type of shops. But all they allow is put something in a cart and that’s it.
Is that because the live demos are limited in functionality?
On my product page the customer should be able to select: Size, fabric-color, fabric quality, print-color###, design*** and of course quantity.

###= A black logo on a black shirt doesn’t sell well so I want the customer to be able to select a logo color.

***= I want to sell customized shirts. The customer should be able to enter some text that should be on the shirt.

This is enough for a first post.
Please suggest themes that do as much as possible of the above.
Perhaps a plugin is needed. That’s good too, even if it costs me some money because a web designer costs far more.

1 - recommended products and 2 - stock management are both very easy to do with WooCommerce

The T-shirt customising is part easy but you may need to add a plugin or else get a dev to work on the part where people could upload a logo or take customisation beyond the initial size and fabric type fields

Is there an Envato plug-in store?

What do you mean? There are tons of commerce themes and plugins for sale but all you need for the above is Woo Commerce official ones

I was under the impression the plugins were sold on this site too.
No problem.
Thanks for your answers.

There are plugins sold on CodeCanyon that will be able to help too / you need to do some homework and work out.

A)which has the best mix of features

B)check there would be no conflict with whichever theme you use (shouldn’t be when it comes to woocommerce)

Yeah, I need to do homework. Lots of it. This thread is the start of that.
I just want to start out with a theme that does most of what I want.
While I’m an absolute WP&WC newbie I do know from experience plugins can cause problems because they aren’t 100% compatible or just aren’t updated (yet) to work with the theme.