Souq.com is quite an interesting website. It is probably the first online shopping website that was offered in UAE and have been around since ages. Their business model has changed over the past and has been restructured a lot over the years. Previously their only offering was from other users that created accounts and listed their own items used/new and sold to other users in which souq.com took a commission of 5% from the seller. After several years they have changed and started offering their own products and started their own sections with Deal of the Day, Warehouse clearance, Eid specials, etc.
Souq.com generally offers a wide variety of products from electronic gadgets to fashion accessories to games and much more. Their offers still include souq.com direct sales and sales from other souq members. Here is where you have to beware. Direct offers from souq are always genuine and authentic, but they are not always the item you might be looking for. For most of you that might be aware that Dubai has a large whole sale trading market for a lot of items mainly located in Deira, Bur Dubai and a few other areas. These wholesale traders normally deal in the parallel import and export of certain items. Lets say mobile phones for example, Samsung has an exclusive authorized distributor in the UAE being Eros Electricals, therefore all Samsung phones purchased from authorized sellers have warranty from Eros. But these parallel imports usually come from Hong Kong, Singapore and UK. Therefore they don't have Eros warranty. Now I assume souq.com has a tie up with some of these wholesale traders for certain products and souq does offer warranty on them, but beware its a Souq.com warranty and not an Eros warranty. The same applies to Apple, Sony and all other brands. Therefore all your claims go to souq so please buy at your own risk. Although if your happy with the price and don't care much about warranty then its not a bad deal at all. Specially considering they offer payment plans from certain banks and returns within 3 days of purchasing any item, which is a very good feature. They will accept any return hassle free and provide you with a refund no questions asked.
On the other hand, they have tonnes of other sellers to beware of. These are regular sellers like you or me that want to get rid of their personal used stuff or unwanted gifts. Again souq charges a 5% fee to sellers once the sale has gone through. If you are comfortable with buying such items, you can go ahead and do so as the same policy from souq applies on these sellers as well where you can get a refund of an item if you request a return within 3 days of receiving it. The risky part with dealing with these sellers is the probability of receiving counterfeits or fakes from them.
Through personal experiences I can say that a lot of sellers either display their used products as new or sell fakes at good prices and try to convince buyers with good deals. Its the same as dealing with websites like Alibaba or other Chinese replica websites, but atleast most of them mention the word 'replica' or look alike or are priced really cheap for it to be true unlike sellers on souq.com.
Generally just beware of some unimaginable deals where your jaw drops and you get carried away in emotion thinking that you got a deal too good to be true, because quite likely it just might be that way.
All in all souq.com has a really good buyer protection so you needn't worry about it and expect a full refund if something goes wrong in your purchase.
I can post a few links to some of these fakes I've come across in the past and answer any of your questions for the future if you have any.