1) As stated, the COL in the manual is what the test organization used. Usually, this is the SAAMI max for TESTING or shorter. This COL is no more than the minimum COL that the data applies to.
2) It as been a "fact" for about 80 years that match/target grade lead bullets in the .45 Auto are loaded to just touch the lede/rifling of the barrel and no one has yet seen any high pressure because of this. This minimizes/eliminates head space and, in almost all cases, improves accuracy.
3) If the loaded round doesn't look right, it probably isn't.
4) reading the reloading manuals will help.
5) For all SWC bullets, you should have, at a minimum, about 1/32" of the shoulder out beyond the case mouth.