I am a Pakistani citizen holding a Pakistani passport , my wife is dual national meaning Pakistani and British citizen and lives with me in Pakistan; we have been married for 7 years and I have travelled to the EU 4 times previously on business with a Schengen visa. I would like to know: does my wife being a British national make it easier for me to get an express Schengen visa or do I have to follow the long tedious process? Also can my visa be denied if we are applying together to visit France? What benefits can I avail by being a husband of a British citizen when applying for a Schengen visa?
No, it does not make it easier by any mean! UK is not even a part of Schengen area and you have to follow the process step by step.
Applying together? if she is a British citizen she does not need a visa for France for a stay of 90 days or less, remember, you still need one.
Bottom lines, Schengen visa process is almost identical in all EU embassies around the world, there are no exceptions. Schengen visa has nothing to do with your spouse's citizenship. The only difference is when applying for a spouse visa to your spouse's home country or applying for another immigration visa.
It all depends if you'll be travelling on your own, or with your wife.
As HaLaBi pointed out, the UK is not part of the Schengen zone. This means that your residency permission in the UK doesn't allow you to travel in the Schengen area automatically. If your wife was French, and you were living in France with her, your residency would allow you to travel within the rest of the Schengen area. She's English, so that doesn't help. If you wish to travel on your own, you'd need to apply for a Schengen visa as normal, no special allowances.
However... The EU allows for free movement of its citizens throughout the area (EU/EEA), and also allows for Family Life. For more information on those, see the EU Charter of Fundamental Rights on the EU Commission or the European Union Agency for Fundamental Rights, or look up Directive 2004/38/EC.
This means that if you want to travel with your wife (but not on your own), then as she is allowed to travel anywhere within the EU, as her family you are allowed to come with her. These two European Commission pages cover a lot of it. You may sometimes need to be issued with a visa, so that border officials know your status, but this can't be denied, and shouldn't be charged for. This has a lot of details. The key part is:
The Europa.EU site has a good set of details on this. Based on the information there, it looks like as your wife is both British and a British Resident, you'll need to apply for a Schengen visa to accompany her to France as a non-EU family member. This should be issued for free and within 15 days, provided you supply the required details to prove your status. (The number of qualifications and warnings around trying for a visa-on-arrival means I really wouldn't suggest you try that one...)