iPhone syncing problems

Hello. I'm going to post this here because these problems only came to light when I switched from my iPod to an iPhone. I'm a new iPhone user. I finally bought an iPhone this past May and even though I like it, it's been pure **** syncing my music from my main library in my iMac.

All of the systems involved in syncing are kept--at all times--up to date. The iMac uses the latest OS X version (Mavericks?), iTunes is also running its latest version. I had held off upgrading my iOS to 8, but I finally did last week and this resulted in new problems.

All of this problems have existed since I bought the phone in May, that is, they existed before the new iOS upgrade, and have continued--the upgrade did not help. Some new issues arose when I upgraded (and I've noted these).

These are the problems for which I would like--if possible--a solution:

1. I've never been able to sync. Put simply, this thing does not work, or, rather, it's wildly unpredictable. It works when it wants to--that's the best way I can put it. I create playlists in my iTunes library but then, when I want to import these into my iPhone, some songs do not transfer. They freeze, or so it seems. I searched for an answer about this and the solution I found was to remove that song which freezes the transfer, restart everything and begin again. This seems to do the trick ... until the next song freezes the transfer again and you have to do the same process again and so on until you're done. Imagine how inconvenient this is when you have thousands of songs to transfer!! It took me a couple of weeks to transfer all my music.
   
2. It (the software? the phone?) wants to upload the music I've bought from the iTunes store. Even though some of this music is not part of my playlists, all the songs appear in my iPhone music.
   
3. [NEW PROBLEM WHEN I UPGRADED TO NEW iOS] The upgrade wiped out all my playlists. They're gone! Now I have to begin the arduous task of importing all of my playlists into my iPhone.
   
4. It appeared that last night I was able to transfer a full playlist, but this morning, when I looked, the playlist was incomplete.
   
5. [NEW PROBLEM WHEN I UPGRADED TO NEW iOS] There is now an app for podcasts, so, even though I carry no podcasts on my iPhone (I load all my podcasts into my iPod Classic), well, I now have podcasts that I can't get rid of.

That's all I can think of, but I think that's plenty for now. Is there a solution to all my problems or am I out of luck? Something tells me I'm not the only one having these issues. I hope someone can help me. Thanks.

Might help to know which iPhone you have?
Must admit, I'm having sync problems with my iPhone 4s and MacBook Pro retina. In iTunes there used to be a drop-down Tab marked iPhone but this has disappeared and today when I opened the MacBook a message said "can't sync iPhone as can't find it - error-50".
I have also noticed that photos are not automatically uploaded to my MacBook. Before, as soon as I came into WiFi range, any pictures I'd taken on the iPhone automatically appeared on the MacBook, this no longer happens??
Any help would be appreciated.