I sell internationally, but not on eBay so won't comment on the eBay-specific stuff. Based on my experience, yes I would recommend it in general, but as I choose not to sell internationally here, I also won't specifically recommend doing so to others. That being said, by and large my experience has been that it is not too different from selling domestically, but can be quite a bit more expensive when something goes wrong, mostly due to higher postage costs, and (if like me and you don't use credit cards etc for anything) you need to have a bit more cash on hand ready at any given time to be able to pay the postage, since you can only pay for international mail (merchandise) over the counter, and a few Pack & Track parcels adds up quick. (You can process P&T labels via click and send, and pay for them with PayPal, but only if you select the option for courier pick-up which is a bit pricey, espcially if you only have a couple of things to go out).
My items are small and light weight, and range in value (from a couple of dollars, to a bit over $100), so I quote letter rate postage, and account for possibly needing to send items tracked for higher value orders in a couple of other ways (eg combined postage prices - my most popular OS items tend to be bought in multiples, so I have a policy of a small amount extra per item, excess will be refunded if applicable, or shipping will be upgraded to tracked instead).
If you're going to be sending quite a few parcels, it's worthwhile to consider Australia Post's Business 250 membership. Basically, if you send 250+ parcels a year, you can get a discount on a lot of parcel services, including some international ones (pack and track, but not registered). You also get discounts on a lot of domestic parcel services that you can't get via eBay such as express parcels (the only ones that are genuinely cheaper via ebay are the flat rate boxes), and it's all pay as you go so no credit or contracts, no lump sum payments up front etc. You do need an ABN, though, so not necessarily suitable for everyone.
When it comes to PayPal, when the buyer and seller are in different countries, the buyer's protection policy takes precedence over the seller's, and most OS PP policies require proof of delivery for seller protection. I recommend becoming familiar with the main PP policies and consumer laws in the countries you're thinking of shipping to, to get an idea of what rights and expectations your customers are likely to have (for example, in the EU, buyers have the right to cancel a purchase for any reason and receive a full refund, including original postage. The minimum timeframe for that is 14 days, but can be up to a year if the seller doesn't specify a return policy - these kinds of things can't necessarily always be enforced on international sellers, but I mention it because it's the kind of thing buyers in EU countries are used to and might expect).
