For the most part, it takes around 2-4 weeks for Emirates to process your claim. It all depends on the demand for that specific month or the complexity of your case. In a particularly complicated situation, it could take more than one month to get it resolved.

No, it doesn’t matter how much you paid for the ticket, as the compensation is determined by the distance you flew over. Even if you booked at a low price in advance or used your miles, you can get up to 600 EUR in compensation.

That depends on whether or not the airline could have prepared for it. For example, if the tarmac is fogged up significantly and prevents the plane from taking off, Emirates has little control over the matter. However, if the “bad weather” is snow at a time when the phenomenon is expected, Emirates should already have the tools necessary to keep the tarmac clear. In this case, the excuse of extreme circumstance doesn’t stand, and you can potentially get compensated.

Yes, but the exact deadline depends on the country you are filing in. In the EU, you have around 2-6 years to file, the average being 3 years. You should research the respective country’s statute of limitations and file as early as possible.