Ted (and paintman
)
Nice. Very good choices and great places to visit, the whole Balkan region has an energy and very different vibe. You won't regret it.
Croatia these days is very European and there's nothing remarkable about motoring. A document check at the border and Bob's your uncle. Be sure to appreciate the Dalmatian Highway is very long and takes a lot of time to traverse, it can also have heavy touring traffic in high season. Many folks have ended up jumping on the motorway to make some time up, self included on occasion. On the coast road may I recommend the town of Karlobag, there's a hotel in the main square overlooking the small harbour and it's a very nice place to be.
As an idea I liked the island of Hvar which is a couple of hour ferry ride from Split. Hvar town is very nice and you can make your way East across the island for twenty minute ferry ride back to the mainland and the Dalmatian Highway again.
For Montenegro, Albania and Bosnia Herzegovinia you will need a green card; expect documentation to be checked properly aside from if you're in transit from Croatia through to Croatia via the small stretch of Bosnia Herzegovinia at Neum (The petrol is cheap there at £1 per litre too
); they don't take much interest in your documents, however if you enter elsewhere you'll need your green card and I'd suggest gaining that cover anyway as I see you're planning to hit Mostar which is in BIH.
Dubrovnik is a beautiful if very touristy place to head to and neighbouring Cavtat is also pretty and not far away.
Montenegro is visually impressive, almost Lord of the Rings landscape in some areas and the ride around Kotor Bay and then up into the hills from Kotor to Cetinje is wonderful. I've stayed in Bar, Ulcinj and the capital Podgorica. All are fine but I can't report anything remarkable (apart from ending up in an Only Fools and Horses themed pub in Podgorica, what a plonker).
Albania is chuckle territory. Very welcoming at the border to bikers on more than one occasion I've been. The main roads are mostly decent although pay attention for missing manhole covers, mopeds carrying hay bales, horses on the motorway and other generally hatstand highway affairs, including unsurfaced gravel sections under motorway bridges (!). The FCO recommend not to motor at night and I think they're on the money. I found the people really friendly and welcoming and have a soft spot for the place, don't let any of the above put you off.
Sarande down in the South is a recommended seaside resort type of place, but with its own Albanian style with good fish restaurants. The road from Vlore to Sarande is special. In Sarande itself I can recommend the Hotel Brilant, excellent accommodation with bikes safely stowed outside the front of the place with a little man watching them.
A point to beware of, if you use Garmin Navigation their maps are very poor off the beaten track in BIH and in places in Albania they are non-existent (Sarande for instance isn't covered). Also, Google Maps don't have proper coverage of BIH for some reason so not good for that armchair planning session.
Slightly off track, but if you end up fancying Serbia do your research on Kosovo as access isn't straight forward.
I also found FYR Macedonia very pleasant with around Lake Ohrid lovely.
Any other info you want feel free to drop me a note..