It seems the first release of Skyrim has a few nasty bugs.

I am currently level 56 and trying to complete the main quest. Trying to use the shout "Call Dragon" and the Dragon never comes. Just get the annoying statement from the Jarl in Whiterun. Something along the line of "Well are you going to call this dragon or not" Not sure of the exact quote...don't have the system up at the moment. The shout initiates by my toon anywhere on that platform but the dragon never shows up. Skyrim guide states it may take a moment but I could wait a week and it doesn't show. LOL Tried going back to an old save and the games always plays out the same way. Got about a dozen others this one is the most annoying. Maybe someone has had a similar experience. Got about dozen miscellaneous quests that seem to be bugged too. One of the other annoying quest is the favor quests for Windhelm is stuck showing 5 out of 5 quests complete but still sits in the active quests basket which I think may be preventing me from getting the house in that city. Still think Bethesda is one of the best games developers of our time. This is definitely a master piece! I also have the house in Riften but no House Carl. Wonder what happened to her? Thinking that may be game design. I sided with the Legion maybe you only get her in you side with the Stormcloaks. But not sure!

Regarding the 'call dragon' shout not working, I've not heard of that problem before. I know there is a bug in Dragonsreach with the main quest when you are trying to call the dragon, but that occurs when you side with the Stormcloaks (but even then, the dragon does show up but doesn't actually attack). I assume you have checked that you have the 'call dragon' shout selected? It may sound like a silly thing to check, but I did the same thing during my play through and I thought the shout wasn't working. When I looked at what shout I 'had' actually selected, and I still had the 'dragonrend' shout active.

After using the 'call dragon' shout, you should hear a distant dragon sound within 5 seconds of using it once. Within 10 seconds, the dragon should be visible from the right. When you use the shout, do you use the full power version, i.e. hold the button for several seconds, then release it? I'm not sure if that makes a difference, but it is worth a try. I did notice that the recharge times are '5, 5, 300', so I assume you need to hold the shout button to get the most powerful version of it.

Regarding your Housecarl not appearing in Riften, she should appear when you buy the house, even if you side with the Imperials (I sided with the Imperials in my play through, so I know the Housecarl 'should' appear). Did you talk to the Jarl after you bought your house? I think it is only then, that you are granted Thane status, plus the Housecal, plus a magic item.

I think the house carl thing is a bug that happens when the Jarl gets switched no matter which side you choose. If you side with the Legion and take Riften by force, no house carl, if you side with stormcloaks but give Riften to the Imperials during the peace meeting on the main quest line, no house carl. I have two seprate characters, both played out on separate quest lines above, neither have a house carl.

Interesting! I was not aware that Riften 'could' be attacked when siding with the Imperials. When I sided with them during my playthrough, I had a mission to defend Whiterun, and then all subsequent civil war missions were attacking Forts until the final assult on Windhelm. So, it looks like the 'no Riften housecarl' glitch is to do with the Jarl switching out.

The changing of the Jarls seems to be causing a lot of bugs in Skyrim. For example, if you side with the Stormcloaks and attack Whiterun, then the main quest gets glitched when you try and capture a dragon in Dragonsreach because the 'original' Jarl is not in Dragonsreach, which prevents the story from progressing (the original Jarl can be found in Jorrvaskr). It is unfortunate that the effects of the 'Jarl switching' on questlines wasn't thoroughly tested before the game was released...

I haven't sided with either imperials or stormcloaks and oversaw the handover of Riften to the imperials for Markarth at negotiations but I still got the housecarl. Also, no problems calling dragon from the balcony at Dragon's reach