Given a travel related situation, and given a specific question about the situation, summarize the question into a title

I received my Iranian visa two days ago. My plan was to go there for a week, but unexpectedly I have an extra week available (due to an event in Turkey being cancelled just recently). Therefore I would like to extend my stay in Iran - to be precise enter the country before the date I put in my application. The itinerary would change a bit too.

Is this a problem? According to the date printed on it, my visa is valid for the entire period. Do I have to notify the embassy or the Police Department of Foreign Affairs or the party, I got my invitation from, about these changes?

What is the best way to handle the situation? I don't want to run into any problems, but I also don't want to miss the chance of spending some extra days there.

Travel changes with an Iranian visa

I'll be going to France for 4 months to conduct research towards my PhD. I believe I will be issued with a long stay visa for research to cover my trip. I have the required "Convention d'Accueil" from the organisation I'll be spending time at. I currently hold an Australian passport.

My question is, is this research visa considered a "Type D", like the other French long stay visas and does it allow entry into other Schengen areas? Does the research visa carry any specific conditions (besides the fact that you need a "Convention d'Accueil" to apply)? 

I will have a month off during my 4 month stay, during which I'd like to travel around to other countries, hopefully I can do this with the one visa.

Does a French long stay research visa differ from a regular "Type-D" visa and are there implications for travelling in Schengen areas?

I am travelling from Prague > London > Dubai > Sydney. 
The Prague to London is with BA and London to Dubai is with emirates. 

They are booked on separate tickets so I don't think my bags will be checked all the way through. Does this mean I will need to collect  my bags and pass through customs and immigration at Heathrow and check-in again for my next flight? Or will BA do it for me?

If I have to, how long does this take at Heathrow? My flight arrives at 12:30 PM and I am non-EU passport holder.

My connecting flight with emirates leaves at 2:15 PM so I only have 1hr 45min to do this assuming the first flight is on time.

Is this possible? Or should I try to make other plans?
Is there a way to fast track immigration or customs? I am a One World Sapphire member.


Do I clear immigration and customs in heathrow T3 for stop over on seperate ticket