Apps to SD card issues

My phone is a Samsung Galaxy Victory running Android 4.1.2. I'm sure this is out there somewhere, but frankly I'm tired of searching and messing around with apps.
Basically, the all-too-common problem: I have a 16gig SD card. Only 11 of those GB are used [edit: actually, 11 free, 5ish used]. Of all things, I should NOT be having storage space issues, but it's something I fight constantly.
I'm tired of clearing the cache on apps every few days and having to log back in to everything. I just want it all on the SD card so I can move on with my life and keep downloading apps.
Further, since I got my new card, my phone is not cooperating with pictures. Every time I open the Gallery, it says I don't have enough space- even though the pictures are saved to the 16gig SD card with 11gigs of unused space. I know it's saving them because they show up in my Dropbox camera uploads folder, but I can't view any pictures on my phone without it prompting me to delete some anyways. (It's also "told" to save them to SD in the camera settings, but since when does a phone of mine do as it's "told?")
I tried downloading this thing called "App Manager," but it hasn't worked well at all. From what I can tell, I have internal phone memory called "sdcard0," and my big SD card called "extSdCard." Obviously I want everything possible on the second one, as the first is only like 1.7 GB. Tried moving everything with the app, but it said it was sending it to sdcard0 and wouldn't let me change the location.
Told it to move all the apps anyways and now have 56kb free space on that sdcard0. Pretty sure I had 144MB before. So...I'm borderline panic mode now. About to clear a bunch of caches just so I have breathing room for now.
Is there a solution for this? Before trying the app, I tried moving just folders by plugging it into my computer USB and cutting/pasting, but that doesn't seem to have been successful as there was no real change in available memory.
On my last phone, it had a "Move to SD" option. This doesn't seem to have it. I had assumed for a while it automatically installed them to SD and I was only getting errors because my 4gig card was out of space, but that should have stopped with this new card. I even uninstalled most of the apps when I got the new card and reinstalled to make sure they'd be on SD and not in the phone. Apparently it doesn't work like that.

In a nutshell, what's the best way to make all my apps that don't *need* to be on internal memory move to SD card?
I'm also slightly open to this rooting thing; I don't know lots about the process, but it sounds like fun.

Thanks! I complain daily about my phone (as I have every phone I ever owned), but so far y'all have done alright in helping me work with this one.

 

Thanks!
I rooted my phone this afternoon (using this/). Actually was easier than expected, although I made quite a few dumb mistakes that would force me to start over, but since I didn't brick it and now have several hundred Mb more space thanks to that FolderMount app, I'm happy. For now, anyways.
Now to just see what else I can play with to make things run better. In general I'm cool with the factory version of the phone interface, but holy cow is it slow. Granted, no slower than any other phone I've had, but slow is slow and I don't like it.