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

[EX Q]: Assuming two different trips - one with a current and one without, what is a reasonable speed to assume for a journey?

First - Norfolk, VA to Bermuda to the Azores to Liverpool

Second - Liverpool to the Azores to Bermuda to Norfolk, VA.  (funny how I did that, no?)

I'm trying to get an understanding of how fast a regular sailboat, not using power, traverses a wide body of ocean, both with and against a current.  A rough order of magnitude for a lesiurely rate of speed is what I'm after here.

As far as size goes, consider a private craft, again, under sail, not engine, maybe 30' - 40'. The idea would be a boat two people could crew and afford :). Feel free to make other assumptions- the idea is to understand if I'm talking days, weeks, or months. 

[EX A]: How fast can one expect to travel in an ocean-going sailboat?

[EX Q]: 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.

[EX A]: Do I clear immigration and customs in heathrow T3 for stop over on seperate ticket

[EX Q]: Upon visa-less immigration to Cost Rica, I would have to prove sufficient funds of $100 per month of residence (Source)

Since I don't expect them to have a dollar-giving ATM before immigration control at San Jose airport and my local currency is Euro, I wondered how I can prove that.

Euros are not accepted in Costa Rica I'd guess. Banks in my area could give me a $100 bill (but none of them could provide Colones yet), but does the next taxi driver have sufficient change to accept it? Or will immigration control accept any bank account report showing I have more than 100 Euro on it?

[EX A]:
Visiting Costa Rica: How to prove sufficient funds?