Lycanth

This functionality is very common, and is also desired by my community. It is provided for in Xenforo's shop add-on, as well as many prior shop add-ons over IPS lifetime. Basically, graphical items for the post bit and profile. They can be purchased and traded. Users absolutely love them. The ability to re-arrange the display of these items, and to pick between, say, the top 10 of them to display in post-bit is lovely. 
I have also requested, multiple times, as have many other users, the ability to buy access to additional usergroups. We like to maintain one primary group (member or staff level) and do other privs as additionals.
Finally, @TheJackal84, members shop is completely broken on my board and results in a Error: Call to a member function url() on array (0) error. I provided more information in PM to you yesterday. 

I honestly can't see the point in looking at someone else's inventory but if enough people request it then I won't ignore the request, it seems like a pointless waste of code to check what someone is holding and not used yet, that would make sense if you had like a award cabnet where you would buy a item what will award you a image or something what can be unique what will show in a cabnet maybe in their profiles as a new tab
Still not 100% sure what you mean by this I have had requests for own images in for items and if you mean instead of a font-awesome icon then yes

So it's basically a new item, I'll see what I can do, It might be a add-on etc but we'll see, also could take a couple of weeks as I have a lot going on at the minute
I have made one already what allows you to pay via points etc in commerce but it was a private one, I don't have permission to make it public ( just yet ) but soon enough I can do it
Somthing like that I would say you just have to maybe do something along the lines of 1 points = 1 cent so 100 points = $1, the dollar won't change it will always be 100 for $1 as if you had $1 in your pocket and the exchange rate changes you $ in your pocked won't ( this can be your default currency not just the $ ), if you are using multiple currencys then the rest could change depending how much of say the £ you get for the $, Don't allow them to cash out, terms can be easily wrote up
Have to check with your gateway providers, but if you are using them to allow purchases I don't see the point of selling them, I would say its long to buy points then use them points to buy something, just pay using the $$$ I used to buy the points with otherwise I am not going through a long process buying 2 things for 1 item each time
people love money lol you see how many people use that silly adfly for like 0.000005 cents for each click loooooooooooool, to be honest it would motivate them more if they knew they could spend them in nexus etc
just don't go silly on the awarding of them, you are not millionaires and don't wanna give $100 per day, if you set it for posts at 1 point per post  then 1000 posts in the day will cost the site $10 so maybe use adverts etc that depending on the company could get that $10 back, I would also not allow the transfer of points for $$$, the points must be spend on site and not transferable for cash
I wouldn't allow that but again it's up to the site owner, it could be profitable especially of you allow member to sell their files etc via points but it could also break you depending how many points the current users hold lol

@TheJackal84 I understand what you're saying and I appreciate your feedback and advice, but doesn't the trophies app do something similar? Also the IPB3 version of shop allowed images to show in the inventory. Would you allow me to hire someone (or yourself!) to modify it to do what I'm trying to?
Also, like the above person I get a blank screen after purchase as well.

No it don't do that, I could add it to the update though
I will sort that for the update, it don't actually use any storage yet so don't worry about filling up your server etc, that is for the coming images what are getting added
Update should be out with-in the next day or two it is only a small update sorting a few things out

the mystery items box will be in the next update

as for the images, I have already wrote like 60% of the code to use them what is inside the app atm, just hidden away, it is something what is coming but requires lots more work and a better way to store them for when users buy and store the items without filling up the server with lots of duplicate images as the items can be created in millions of different ways per item etc and could all maybe be using different images
I am also thinking of maybe adding a win % to all the mystery points etc, if you set it at 70 then a user has 70% chance of winning with 30% chance of losing and getting nothing

I am really wanting to purchase this for my site, but want the ability to use my own images for items as well as have a mystery box that, when opened, will give a random item from a predetermined set of items.
Will these features be added, or can they?

^^^

Yes please! 

I know this might be a bit of a stretch, but what if we dont want to use FA icons for the shop items? 
Just a little assistance with the following:
Is the membersshop_custompurchases" table only for items that are redeemed? How can I have the html appear properly for rewards log?

Adding images instead of font-awesome icons is next on my list of updates
To be honest I didn't think about the medals I only done trophies, I will look into it and see what I come up with
I will add it to the list