How to check status of an order on BTC-e API? It would appear there is no way of obtaining fill notifications for active orders.

If I am mistaken, please enlighten me!

When orders are submitted to a BTC-e account, either via API or their website, and they are NOT instantly filled, they get assigned an OrderID integer. I can query the authenticated API for account info, which will give me back a list of all Active Orders and associated OIDs, but aside from having my program maintain a list of what it "thinks" are Active, versus what actually is active on the account by sending a query every X seconds, I do not know of a simpler/faster way to determine what orders got filled or when.

I also would like some clarification on the status field of the order response from API. it would appear 0 is active and 1 is filled. What are the values for partial fill and cancelled? 

There is also a way to see All orders on the website by going to Finances->Orders History and then the drop down for Show All, is there a corresponding API call for that?

I need to be able to monitor for partial and complete fills.
It appears you are looking at "active orders" if you are seeing this status. As per BTC-e API documentation (found at: https://btc-e.com/api/documentation), you should be looking at trade history, which will show completed orders. Partial orders would show as individual trades on as the result e.g. if you place a sell/ask order 1 BTC @ $1000 and I were to place a buy/bid order of 0.1 BTC @ $1000 then you would see a trade of 0.1 BTC @ $1000 in your trade history, if I were to place the same order again against your 0.9 BTC remaining you would see two trades for 0.1 BTC @ $1000. This data is shown here for partial trades even if the order is still active.

Since the standard output is limited to the 1000 most recent transactions, I would recommend making use of the 'from' parameter when scraping trade data. You can increase the number of results but BTC-e will likely place a limit on how much data can be returned at some point in the future. You can also stagger API calls to get 1000 transactions at a time, however I would recommend putting this data in a table for better access.