No, this pool has no need to change the extranonce values after a connection has been established.

You are probably not taking the network difficulty into account. The PPS ratio went from 340% to 380% recently, but during the same period the network difficulty also went from 8918390 to 9917510.
At any rate, you can see a detailed breakdown of how your rewards were computed if you click on the "View full history..." link on your account page and then scroll down to Lifetime Rewards History.

The email address for support is support@ litecoinpool.org. There is a link to it at the bottom of every page on the website.

You need to send an email to support ASAP. Make sure you include your username and explain the situation.

We don't have a chart, but if you click on "View full history" on your account page you can see your full rewards history broken down by PPS rate.

Only if they can be merge-mined with Litecoin.

Of course. Expected rewards are linear in the hash rate.
You probably want to check out the mining calculator on the website.

Thanks. It seems that Coinbase discontinued the API we were using to fetch some of the prices. We've switched API and the price is now updating again.

Could you please send an email to support with your username, specifying what number stopped updating and when? Also, keep in mind that 24-hour stats are only updated once an hour.

A script on the back end periodically does the math and conservatively adjusts the ratio when appropriate. We can also adjust it manually, of course.

At the moment it would all depend on when exactly you'd trade your coins. The price of DOGE has been going up and down by as much as 30% just over the last 12 hours.

Since unlike F2Pool we do not pay out LTC and DOGE separately, relative profitability keeps changing, especially now that the DOGE market is so volatile.

This pool mines both, but everything is converted to LTC and payouts are in LTC exclusively.

There are lots of factors we have to consider whenever the PPS ratio is updated, including relative market prices and liquidity, network difficulties, etc. The price of Dogecoin has notably been experiencing huge jumps in both directions lately, and that is indeed the main reason why the ratio has been going up and down a lot.

Yes, we've received it. We need to run some checks on the account, we will let you know via email as soon as possible.

That email address is the correct one.

Changing a locked address is generally not possible if you no longer have access to it, but at any rate your only chance is to talk to support over email. As of this writing, all the support requests we've received have been handled, so if you haven't received a reply, make sure you have the right contact details and send your email again.

I don't see any reason why you shouldn't be able to use a Gridseed on the pool. The hash rate might take a few minutes to register, since it's quite low, but it's been that way for years now.

If the worker's name shows up in green on the website, but the hash rate remains zero, it means that the miner is connected but not submitting any valid shares. This could happen for a number of reasons, the most likely of which is probably HW errors, which in turn is often caused by a bad or insufficient power supply.