I personally wouldn't go the CON+SIZ route for Total Hit Points, it tends to make the PCs feel like MMO tanks and almost invincible. I prefer my PCs to know they can be hurt easily, but I usually count 0 HP as Incapacitated rather than Death, as its not fun re-rolling characters mid-campaign. I would keep usual Hit Points and Major Wounds as they are.
Liberal use of Luck Roll or Hero Points can easily add to a more pulpy flavour and keep the characters out of harm's way.
Simple approach for BRP is allow for wide spanning outcomes with a Luck Roll, although give it a cost in Power Points, aka Fate Rules options from BRP. As you are using OpenQuest, you can pretty much cover this with Hero Points, and porting over ideas from Astounding Adventures Action Points are a great idea. So you've got all you need already there.
If you allow for a wide scope of situations with Hero Points then you'll be right. Perhaps include Attribute x 5% rolls for general situations that you have no skills involved, such as Idea Rolls etc, and use Hero Points to augment mundane skills beyond the usual scope, allowing for highly cinematic outcomes, for example, Athletics could be used with a Hero Point to cover very swashbuckling cinematic moves, etc.
I think if you are regularly awarding Hero Points then you will give the characters a currency to do cool stunts and extend their survivability. I would award a Hero Point or two for achieving certain minor objectives during game play, or if a scene is roleplayed well. Doing this during game play will allow the Hero Points to build up quicker, and you can always award a few more at the end of a session for achieving the major objectives of that scenario.
Just throw out Hero Points here and there, and you'll soon see the characters using them to get out of scrapes etc, and it will add to a more cinematic feel to the game, which is usually a winner with most troupes. Works well for my group
Edited by Mankcam, 23 February 2014 - 01:24 AM.