#1 Yep, as Perry said, the Germans had PF with a range of two hexes (June 1944 as per ASLSK RB 4.4.2 p.20 3rd para). A respectful distance was, therefore, kept throughout. As it happens the Canadian Shermans were mainly operating in a supporting role, providing WP, Smoke & fire support to the infantry, so keeping their distance fitted that role well. The Firefly took a calculated risk to the east of Rots in an attempt to get a shot on the Panther and to force it to relocate through the LOS of the PIATs. I also wanted to start complicating the Germans' potential rout options (especially in the mission critical R1 multi-hex building).Two comments here: #1. Are there panzerfausts in ASLSK? If there are PF, this would be an advantage to the German though it seems as if the Brits kept their distance (3+ hexes) from the German infantry.
#2. Yup, intensive fire is fickle and best left for absolutely necessary circumstances. Murphy's Laws of Combat most usually apply: Thing will go wrong in combat and it will most likely go wrong at the most critical time.
#2 While I was definitely distinctly injudicious with the use of IF in turn 2, I still used it again in turn 3 and you can see where a PIV used IF to dispatch one of the rapidly disappearing T-34s in tAA6. So again, I’d agree with Perry in saying that at the right time it’s a very useful tool. I think you just have to weigh up the necessity of taking the shot (in turn 3 if I hadn’t, I would have lost the game) against the negative consequences of potentially malfunctioning the main armament. I was very lucky with the Tiger which repaired its main armament and – with the benefit of hindsight – I shouldn’t have employed IF with it in turn 2. And I wholly agree with your suggestion of always bearing in mind Murphy’s laws of combat (for example: “whenever you have plenty of ammo, you never miss. Whenever you are low on ammo, you can’t hit the broad side of a barn.”)