I have some questions/suggestions regarding the BattleMech Manual, which aren't quite errata, but probably should affect a future (re-)printing of the product:
On page 8, the book has a mini mech sheet illustrated, but the book has no full size sheet in the back, given the denseness of the sheet, having a full size version in the book would seem like a good idea. Given the new soon-to-be-released starter set, I would suggest considering to include full size mech sheets for both the Griffin and the Wolverine in the back of a future edition of the BattleMech Manual. (BTW the mini mech sheet on page 8, still has the old battletech logo :)
On page 22, Line of Sight paragraph, the paragraph talks about when line of sight overlaps a hex-to-hex border exactly, where the defenders gets to choose which hex is used to terrain rules purposes. However then the rules refer to the Line of Sight between two hexes diagram, which suddenly drastically changes the line of sight path, from an undefined point in the attackers hex (as opposed to center), to the same, but still undefined point in the defenders hex. So the rules seem incoherent with the diagram, and the diagram itself isn't unambiguous either. My guess is that the rules are correct as written, but the diagram is misleading. Especially since the diagram itself doesn't make it clear that these alternate paths may only be taken when the primary line of sight path runs perfectly along a hex-to-hex boundary.
On page 47, the Ammunition Critical Hits Effects paragraph is a bit terse on how to calculate damage, and the examples given, assume that you know some weapon statistics by heart already. The Missile Launchers bit on page 102, does a much better job of explaining critical hit damage. Please consider changing the wording on page 47 to something more in line with better example on page 102.
Why isn't the BV2 Pilot Skill Adjustment Table (TechManual Pg. 314?) included into this book? It would seem rather important to be able to balance out a force point wise, and lugging around the TechManual just for pretty much one table isn't great either. I would argue that a future edition of this book should have this table for reference at least in the back of the book.
Also it seems the BattleMech Manual is missing generic scenarios (or any scenarios at all). Given that the BattleMech Manual is all one should need for mech-on-mech combat, I would have expected 6 (so D6 randomization is easy) well playtested generic scenarios (similar in concept to the, unrelated, scenarios in the Alpha Strike Companion).
The BattleMech Manual also seems to miss an index, but I'm probably not the first to point that out.
I hope you'll consider the above for a (hopefully soon) reprinting of the BattleMech Manual.