here's my take on a few

rifling - button rifling is done by forcing a high-tensile plug through the barrel blank. the plug has raised ridges on it's surface which cut the rifling grooves as it passes. hammer forging involves placing the barrel blank on a grooved mandrel and hammering the living daylights out of the blank until it takes on the form of the mandrel (the blank starts off around 12 inches long and finishes up stretched to 24-inch plus). hammer forging is much quicker than button. the big manufacturers (sako, remington etc) use hammer forging. specialist barrel makers (krieger, for example) use button. which is better is debatable. you can get good and bad ones with both methods. hammer forging requires more critical stress relieving of the steel.

crown - the muzzle end of the barrel. the muzzle is usually crowned ( recessed ) into the barrel end to protect it from knocks/damage. target riflecrowns are often hand finished

free-floated - the barrel makes no contact with the stock forward of the receiver-ring. in general this is highly desirable. as the barrel heats up, it can expand. contact with the stock results in pressure changes on the barrel, and can shift point of impact. however, on lighter, thinner barrels, a fore-end pressure point can sometimes seemtighten up the wippy vibrations that run through a light barrel. if you can get a free-floated factory model, do so. if not, getting it free floated probably will, but may not necessarily, producebetter results.

Bolt lift - the amount of travel required to lock the lugs into the receiver. some actions require 90 degrees of rotation, some are down to 60 degrees. the less rotation, the faster you can cycle a new round in. it is basicallya function of the strength of the locking lugs.

locking lugs - the more lugs, the more evenly the backthrust is spread. weatherby mark v actions have up to nine smaller lugs. the vanguards, tikka's etc have two opposed large lugs. in theory, more is probably better, but they all have to be loaded equally to maintain balance.

1 piece bolt- smoother cycling, less tendency to bind up.

bolt knob- knurling simply provides a grippier surface for fingers. never had a problem with smooth, myself

fluted bolt- has channels in the bolt to allow high pressure gases to escape away from the shooters face in the event of a ruptured case or primer. most (all?) modern actions have some way of deflecting the gas away for safety.

three rings of steel - the case head is surrounded by a) the barrel, b) the receiver and c) the bolt face. provides good safety for the user, and probably minimises case head expansion.

detachable mags - i like them. easy to unload the rifle when climbing, driving etc. carry a spare in your pocket for fast reload. hinged floor plates are ok. i don't like blind mags, because you have to keep cycling the bolt to unload.

bedding - a can of worms. some rifles have aluminium pillars cast into the stock that the action beds onto. others are "glass bedded". some simply bed onto the stock material. pillar bedding seems to be the current preferred method.

there you go. these are just my opinions/ understanding of some items. there will be many more knowledgable folks out there who will disagree or clarify things for you.

cheers, jason