Smooth Lefty,
Spares are and always be an important part of the game. They are difference makers. As for the swing-side corner pins, I got two suggestions. The first is to get out there and just practice at picking them up. The second is, next time they start showing up and mind you this'll only work if the ball was thrown well, move a half board back to the left and continue to throw like you were. That should take them down. I find that most people believe their corner pin spares to be the bane of their bowling game. Me and the 10 pin have no problems. It understands that if it stays up when I hit the pocket, it gets a ball all to it's lonesome. I think its a Masacist myself, cause boy do I punish it some nights.
I apply or rather, I'm learning to apply four basic types of axis rotation. I do it by working the inside of the ball and then leading with whichever finger corresponds with the selected axis rotation.
Here Joe Slowinski and cgeorg explain it pretty well.
http://cmgbb.wordpress.com/2008/04/03/axis-rotation/http://bowlingknowledge.info/images/stories/slowinski_4_point_btm_nov_2006.pdfAs for the mental game, it varies from person to person. For me, I realized that anger never will, is, have or ever going to help. And I know exactly when I realized it. I saw a really good bowler (210+ average on house shot) go from a 250+ game and get a couple bad breaks get angry hit stuff, slam the ball down, all that stuff. He went from 250+, to 190 to 160 something. Not a great night. I decided then that anger was never going to help. So I laugh. Ten pin, no biggie, a tiny adjustment and that problem's solved. 4 pin tiny adjustment and that problem is solved. Ball's
rolling to early, ball speed adjustment and that problem's solved. I guess you could say that being open-minded, versatile and most importantly learning to adjust at that correct times and ways quells anger immensely. I'm not saying it is the difference between perfection and an all spare game. It can be, but instead of the ball and the lane being the variables and to blame for miscues, I accepted that I'm the variable and when something happens that is unexpected, I have to change.
Case and point, last week I threw my first 600+ series in a while. In practice and the whole night everyone was complaining about dry lanes and not being able to use the equipment they wanted to. Well I focused on reading the lanes and adjusting accordingly. I was focused, threw a couple bad shots, got some luck, and NEVER CHANGED FROM THE BALL I STARTED THE NIGHT WITH (and still managed to be high man on my team)). Over the course of the night I moved from about 22 over to 29 at my start point and my target went from 10 to about 13-14 at the arrows. I changed my finger position once, my axis rotation twice, and I increased my ball speed towards the end. Overall, I was extremely happy with the night. I had plenty of spare conversions and made all of the makable ones. 3 splits were my only sour spot. My point is that, I was about to instead of getting angry, I made light of a "mistake" and adjusted of the data gathered.
As for teammates, I run into issues with my older teammates. Typically men and women who have gobs and loads more bowling experience than me. And because of the age difference there is usually a difference in style hence different dynamics. For instance, where my dad lofts the ball, I lay it down at the line. He pushes the ball out, I use a swinging-hinge. Firm for him means grabbing the ball, for me it means an increase in ball speed. He loves 16# equipment and will preach it up and down the street. I prefer something along the lines of a heavy 14 to mid 15lb ball. As you can see it is a little tough. Plus some of my teammates give me blank stares when I bring up things like axis rotation and tilt, free swing and things like that. My biggest one is when I get too far forward in my approach, it causes me to not be able to get my shoulder back around so my ball sails out to the right and seldom makes it back. I get lots of you should do this and you should do thats to which I reply...or I could just keep my back straight. It comes down to knowing when and what advice is good and your own game.
This doesn't mean I can't learn anything from them. Another set of eyes watching you will always be a benefit to you. I've had some people tell me things I was doing in my swing that I wasn't even aware of. I fixed it and went on my marry way to strikeville.
As for the added pressure, my only suggestion is to put the ball down, ask them if they want to win, and then calmly tell them to never interrupt your pre-shot routine again, and then start your pre-shot routine again. And if they give you lip, "accidentally" let the ball go in their direction on your backswing that always works. JK

You have the right attitude. Short term memory is the right idea, but like I mentioned above, instead of thinking, dammit I left a 4-9 (while that does suck) it is a makeable spare. So think instead, alright I need to adjust. Scores are for the end of the night or unless you are the scorekeeper like me. I look at the scoreboard only to check what lane I'm on if I'm not writing something down.
Well I probably gave you more info than you wanted or needed but hey...I hope it helps.
The Demolition man