WojtekSz
In answer to your combustor question concerning LCF, just about everything you mentioned is done to improve combustor life. Primarily, I am more familiar with combustors that are not lined, meaning nothing is disposable, but other combustor designs use tiles that can be replaced. The liner walls are cooled with air through a series of small holes to provide a film of cooled air. The flame side of the liners are thermal barrier coated to reduce the magnitude of thermal gradient, e.g. cold - hot - cold. Attention is paid to rounding all edges to minimize potential crack initiation sites. Regardless of the extremes this component sees, they last a long time. Life is very good on engines that fly long distance routes, 10-14 hours in the air, fewer cycles and long hours. There are set periods of time/cycles where boroscope inspection of the combustor is done on wing. If an engine comes off wing regardless of cause, the combustor is inspected. At a specific set time, the combustor is removed and weld repaired as necessary and reassembled with time starting as if it were new. This can typically be done 4 times before it is scrapped.
I should add, the newer combustors utilize twin swirlers that perform better to mix the air with the fuel creating a leaner burn, lower temperatures, improved fuel burn and longer combustor life.