2) 5kg gain of lean muscle on this cycle. I think would be close to impossible. I think if you gain half of that it should go down as a pretty successful cycle. If you do want to gain 5kg I would say do Test (I know you said you don't want people saying that but the truth hurts.........You said you have already noticed people saying it on this and other forums - its not because people are trying to bully you into doing things their way, if I thought you would achieve your goal of 5kg on Anavar only cycle I would say go for it. People say do Test because they generally have more knowledge and experience of AAS than the OP, and they realise that that is what is necessary to achieve their goals.
It should be noted that in theory if one was to consistently suppress your natural estrogen levels for a long period of time, this would negatively impact your health, including your cholesterol. Due to the ability of Letrozole- to inhibit estrogen so much, this should definitely be a concern to most users. However the research that has focused on the relationship between use of letrozole and cholesterol levels is rather inconsistent in it's findings. Many studies have concluded that the compound is detrimental to both a user's HDL and LDL cholesterol levels, while other research has found no link. Obviously individuals are best served to monitor their cholesterol while using any compound via blood tests however barring that, letrozole should simply not be run for extended periods of time if at all possible. Doing so could cause serious medical complications.
Along with the issues related to blood lipids is the fact that many users complain that their libido is dramatically reduced when using the compound. This is related to the fact that estrogen is partly responsible for the regulation of an individual's sex drive. Since Letrozole- is so potent it can often drive estrogen levels too low and this inhibits a user's libido. To avoid this users can lower dosages, but some anecdotally report that even extremely low doses of the drug can cause problems. If this is the case a less potent compound such as exemestane or anastrozole may be a more appropriate option.