Skrill (formerly Moneybookers) got their start in processing payments in the e-Gambling industry.
They essentially got their start processing in the e-Commerce industry. From the gambling side (which they have been distancing themselves from), they got into virtual asset transactions primarily for Europe.
A little bit of history, but PayPal largely got their start from the RMT industry as well. For two years, we were their largest client prior to eBay purchasing them. Once this happened, PayPal's focused shifted to tangible payments, and they became less focused on supporting digital asset exchange.
This however never happened with Skrill, and they continue to be supportive of the RMT industry. That being said, they will still consider you a high risk merchant, and will therefore charge you very high fees, and there is still the risk of chargeback, but they are still much better in being able to handle fraud for this industry than PP.
If you are really worried about chargebacks, then I would recommend setting up a store on PlayerAuctions (shameless plug, I know). There you'll be able to offer most large payment options to your buyers (PayPal, Skrill, Neteller, Direct Credit Cards, Western Union, Bank Transfer, and a few more we are opening up soon), and all of this will be protected by chargebacks for you. We've been transacting digital goods since 1999, and therefore have the largest, and most comprehensive warm, negative, and black lists on the market, combined with our risk management tech, we are able to keep fraud very low, and absorb it on behalf of the seller when it does occur. It is just important that you follow the secure seller delivery agreement to make sure you are protected. (I really didn't mean to sound like a commercial)
As for spending limits/receivables, there can be limits depending on the type of account you are approved for. And if your volume/chargeback ratio meet certain thresholds, then you may be required to have a "reserve" on your account to continue transacting (a holdback reserve of funds which they hold on to as a security. Kind of like a deposit). At PA you won't need to worry about any of that.
Regardless, best of luck with your store, and stay safe!
~jake