I am not paranoid at all, I just tend to be careful because I already had liver problems years ago and I read somewhere that it is ok for an healthy liver to cycle 16 weeks, but if you have some problems with amonia excess production you should reduce it to a maximum of 10 weeks. I just have that doubt, nothing more, I'll do my things but want to be a bit carefull.
It's good to be careful. Generally speaking, there should be no stress from injected gear. The stress caused by oral steroids is caused by the alkylation or methylation used by the steroid to avoid destruction by the liver during first bypass. Without alkylation or methylation, the liver would destroy the steroid so there would be none available to enter the bloodstream. Injectable steroids go straight from the muscle to the bloodsteam and everything the bloodstream goes through, so although they eventually go through your liver, they don't need the protection from first bypass. By way of the bloodstream they will have already bound to the AR.
Almost forgot...if you have a choice, I would use cyp or enath over sust.
Information about the toxicity of orals on the liver come from studies done on AIDS patients who are sometimes prescribed anabolic steroids to prevent muscle wasting. The study used 150mg of anadrol a day for 18 months. Of course no bodybuilder uses any oral for 18 months (especially anadrol). At the conclusion of the 18 months, they found that the patients had elevated liver values. Elevated liver values can be an indicator of liver damage, but are not conclusive evidence. By the way, liver protectors also cause elevated liver values. After the patients quit using the anadrol, all of their liver values returned to normal and that is in someone who has a compromised immune system from AIDs.