Ok I wasn't quite sure where to put this so mods feel free to move!

I'm going to SFO in a few weeks but have had to rebook because of important commitments that came up short-term. Because of this and the fact that the guy I'm going with is going on the flights I was supposed to go on I was locked into a tight set of dates.

Bearing this in mind, I booked my new flights last night. The best I could get for a reasonable price was ORK-LHR-PHX-SJC on the outward leg.

The big problem is a 1hr 30min connect time in LHR. I know, I know, very foolish but it was my only option given my restraints.

So, a few Q's:

1) Has anyone here made a T1 to T3 connection like this? How tight was it?
2) Last time I went through T3 security it took 1+ hrs, has the opening of T5 made any difference?
3) The official website gives 2 options for transfer: moving walkways (11 mins walking time) or the bus that's supposed to go every 6 mins (last time I took it it wasn't close to as frequent as this). Which is faster? Bear in mind that' I'm an insanely fast walker and usually when a site gives a walking time I can halve it
4) Which security checkpoint in T3 is the fastest? Is it true that, coming off the T1 bus, you go through an airside security checkpoint which (may or may not) be faster than the landside checkpoint I'd have to go through if I took the moving walkway?
5) How does the time of day / day of week impact security lines? I'm Trying to make a 14:35 coming off a 13:05 arrival. It's a Saturday
6) Any chance of the rumored/planned EI move to T3 being done by the 28th of August?

What I'm already planning on doing to maximise my chance of making this:
-check in online 24 hrs before ORK flight to get seat as far up front as possible.
-checking in online for BA flight and either taking no checked luggage or checking it through from ORK.
-checking departing gate for BA flight that morning, pdfs of LHR terminals on laptop so I can plan my walking/running route

Having said all this it wouldn't be tragic to miss the flight because the ORK-LHR segment is on same PNR and a codeshare so BA has to get me to SFO regardless... right? I'm also above BA's min. connection time. It would just be a shame if I missed it because I want to get to my friend in SFO asap.

I hope I havn't missed anything obvious here, still within 24hr cancellation window so if I have please tell me

Many thanks in advance,
Happy Flying!