You have various options. See here: https://bitcointalk.org/index.php?topic=482352.0

As far as I know cgminer 3.8.5 does not support scrypt mining.

Yes, of course. We've also been among the first to switch to v3 blocks a few weeks ago.

Because the profitability of merged mining has gone down significantly in the last few days.

There was a soft limit at 65,536, I've bumped it to 131,072 now. If you need anything higher than that just send an email to support, but keep in mind that 65k was already pretty high. For a 500 MH/s miner, 131k corresponds to an average of one share every 17 seconds.

If your miners show up as online but no shares are being submitted then I'm sorry but you are indeed running them for no reason. If that's the case, almost certainly something is wrong in your configuration.

I agree. I have now decreased the minimum interval between updates of the user API from 1 minute to 10 seconds.

Great to hear that. I was just about to suggest trying to upgrade the miner. BFGminer is (just like all cgminer forks) a rather complex piece of software, and you never know where the next bug is going to pop up.

Probably not. Older versions of BFGminer only display the integer part of the share difficulty, so 0 is expected if the difficulty is less than 1. (More info about BFGminer's way of formatting difficulty here.)
Also, if the difficulty were really 0, you would be submitting a lot of (invalid) shares. And I see that your miner hasn't submitted a single share yet.

Version 2.4.2

• Added support for Stratum over SSL/TLS. (Please note that official binaries do not include OpenSSL support, so if you want to use this feature you will have to build from source.)
• Creation of version-3 blocks with getblocktemplate is now allowed.

The source code is, as always, available at GitHub. Source tarball and binaries are available at Sourceforge.

Read, read, read. I can't stress that enough. This should be a good starting (and for many, ending) point:
https://www.litecoinpool.org/beginners-guide

Scheduled maintenance for tomorrow, March 3, 22:00 UTC (only affects website and Tor hidden services)
https://www.litecoinpool.org/news?id=64

Version 2.4.1

• Added full support for scrypt(N, 1, 1) (e.g. --algo=scrypt:2048).
• Added optimized PowerPC code for scrypt and SHA-256d. Both an AltiVec version and a plain PowerPC version have been included (compile with --maltivec or --mno-altivec to choose). The AltiVec implementation is currently optimized for the 74xx family (PowerPC G4). Observed performance: 2.06 kHps/GHz for scrypt, 987 kHps/GHz for SHA-256d.
• It is now possible to use getblocktemplate with merge-mined cryptocurrencies.
• The miner will now automatically switch to getwork from getblocktemplate if no payout address is provided.
• Fixed a couple of security issues.

The source code is, as always, available at GitHub. Source tarball and binaries are available at Sourceforge.

Looking into it, but it doesn't seem to be very profitable right now judging from its current difficulty and market price.

Sapphire doesn't seem to be doing too well: its network is very small, people don't seem to care about it, and there is almost no buy support.

GreenCoin has been officially abandoned (see here).

Right now we are merged-mining:

• Dogecoin
• Viacoin
• Umbrella-LTC
• Syscoin
• Pesetacoin
• Tacocoin

Some of the coins you list (such as Catcoin or Digitalcoin) are not merged-minable, and some (such as UnitedScryptCoin or Burbucoin) are simply dead.

Thank you for posting, I didn't know that Viacoin was adding merged mining support.
I have installed the Viacoin daemons and they're currently downloading blocks, hopefully we'll be ready to start merged-mining VIA very soon.

UPDATE: Viacoin merged mining is now up and running. PPS ratio has been upped to 115% (don't expect this to last long, though: the difficulty of Viacoin is going to rise quickly as more pools start merged-mining it).

No idea what you're talking about, payments are working as usual.

I see you just requested a manual payment, and it worked perfectly. You could just have waited half an hour and you would have received an automatic payment.
Regarding automatic payments, keep in mind that (as explained on the payments page) 1. they are processed once per hour and 2. in order to prevent transaction spamming, you won't receive automatic payouts more often than once every 3 hours.

No, CPU mining is not profitable anymore. You must have given a wrong hash rate to the calculator. Mind that the online calculator takes a hash rate in MH/s, not kH/s. And 90 kH/s = 0.090 MH/s.

The share difficulty has no influence on expected earnings. You can find more information on this in the FAQ.

You didn't say what GPU you're trying to mine with. There is nothing intrinsically wrong with the screenshot of bfgminer that you posted, it only looks like your GPU mines extremely slowly. If you have an Nvidia GPU, you should try cudaMiner instead of BFGminer.

By the way, let me remark that nowadays GPU mining is hardly profitable, even with high-end GPUs.

Also don't forget to read the documentation.
https://github.com/luke-jr/bfgminer/blob/bfgminer/README.GPU
https://github.com/luke-jr/bfgminer/blob/bfgminer/README.scrypt

You forgot to add "--scrypt". Without that, you're basically trying to mine bitcoins.