To me the best information is webgl demo > video review > advertising video > screens > text. That being said a well done version of any combination of these can do the job but the more is better. If curation of the store is a priority then part of the curation would be to make sure the items do not convey a false sense of the product whatever the medium is being used.
Casual 3rd party reviewers are fine, but generally only really cover what they are interested in and reputation does matter which is something a casual reviewer struggles with. Usually the professional reviewers with a known reputation is best and they can certainly grow out of being casual to being professional but that is usually supported with dollars from views, but also dollars from affiliate marketing, and a good voucher system so that the well known reviewer doesn’t have the cost of all these packs. Epic is struggling at the basics, so I don’t see an affiliate traffic system as something that is coming anytime in the next few years.
Moderators being paid with credit is fine, but generally cash is better. With how small the marketplace is currently moderators might do, but it won’t scale. Realistically, they should hire more in-house staff. While I’m sure you are good hearted, any 3rd party does open it up for some abuse.