
When raw feeding heart is usually classed as muscle meat so you wouldn't include it in your offal allowance. Offal is usually fed at around 10-15% of total diet - I use liver predominantly and kidney as and when they are cheap to buy.
My dog seems to be best suited to between 20-30% raw meaty bones - with the emphasis on meaty - and I usually feed either breast of lamb with the bones in (this is different to lamb ribs which are far less meatier), sometimes chicken wings and fairly often the value chicken portions that Tesco sell which consist of legs, thighs and quarters in varying quantities. I also feed tinned pilchards as part of the bone content about once a week.
As I use AMP mince this has up to 5% bone content anyway so that is included in my calculations. Once or twice a week I feed a raw egg with the shell on as an extra or if the bone content has been low that week.
If you are able to source your foods from companies such as Landywoods you can save significant amounts of money - they don't deliver to our area sadly but with just the one dog it is not too much of a problem cost wise.
I have never minced bones up as Harely eats anything in it's natural state but, reading posts on various raw feeding sites, it woud appear that a normal household mincer won't put up with prolonged use on dog bones.
I tend to try and have as much species variety as I can and use beef, lamb, chicken, turkey, rabbit and fresh fish (live in a fishing town) - pork is usually restricted to liver and kidney purely because of the cost.
The best way of assessing if you have the bone ratio correct is by seeing what is coming out the other end

You don't want crumbly white offerings as this means that the bone content is too high and you certainly don't want anything that will dent the ground when it hits it :D
Hope that helps a bit - it is quite daunting when you first start raw feeding and can take a while for you to feel confident with it :)