Jigster\
You've got some good moves here! Your BFM terminology is a little off...let me help you out.
To start with, we need to understand that a BFM maneuver is described with reference to the bandit...not the horizon. So, when we talk about a Low Yo-Yo, the 'low' is in reference to the bandit's flight path...not where the ground is. A Low Yo-Yo could be flown in any direction...up, down...inverted, right side up, etc.
In your first maneuver, let's delete the term 'low yo-yo'...and replace it with the term 'slice'.
The maneuver you describe is an excellent bid for turning room in the vertical, followed by a slice that takes full advantage of Radial G to complete the turn in the least time. Good job!! Let's look at each part.
>>After pulling up and away out of the attacker's flight line (up about 30 degrees or more, and roll between 60 or 30 degrees left or right) and gaining slight seperation<<
Thsi is your bid for turning room. You could go in any direction...you chose to go 'up'. ('up' in this sense is with reference to the ground.) This is particulary good if you have a little more speed than you need...you can use the short climb to bleed that speed as you get separation 'above' the oncoming bandit.
Once you have your nose commited 'up', you can unload and roll to keep the bandit in sight as you orient your lift vector for the upcoming pull 'down'.
>>I normally roll close to 180 degrees and pull hard which puts me in either a low yoyo, or a Split S depending on bank.<<
Split S...yes! Yo-Yo...no! A Low Yo-Yo is a form of acceleration maneuver used against a turning bandit when you do not have the ability to speed up and catch him...so you use a descending cut-off (with reference to the bandit's plane of turn) followed by a climb back up to the bandit's flight path. The cut-off and the descent provide the additional closure needed...so the Low Yo-Yo is used to catch up to a bandit (acceleration maneuver)...not to change direction (turning maneuver).
Here, I think you are using the term 'yo-yo' to mean 'descending turn that is on an oblique angle relative to the horizon'. The correct term for this is 'slice'.
Once you have gained the needed separation in your 'pull up', you roll to orient your lift vector back in the direction of the bandit (whom we presume is still flying straight ahead, fat, dumb, and happy...not a good assumption, but that's another story!!). If you orient your lift vector straight down, using the ground as a reference, then your next maneuver will resemble a Split S. If you orient your lift vector on an angle less than straight down, you will perform a 'slice'. The major difference between the two is the amount of altitude lost in the turn back.
>>I end up behind him with most of the energy preserved...in normally what is a good offensive position.<<
The reason for your advantageous energy state is that you have used gravity to increase your Radial G (min turn radius, max turn rate) while minimizing airspeed loss.
>>Now I have used bunts before, by rolling inverted before he gets into gun range, and pushing forward...<<
For a HO situation, I see little value in doing this. If you want flight path displacement in the shortest time, use positive G. While you may be able to keep the bandit in sight while doing this negative G bunt, the sim's AI should red you out very quickly.
OK!! So much for the academics. You have the right moves...you just needed a little polish on your terminology!
Andy