1.) yes but make sure you ween off of it, so instead of getting off of it cold turkey, plan ahead a few months to lower dose as low as you can and then once you're off of it completely for a month straight, conceive. It doesn't have a long half-life " The terminal elimination half-life (t1/2z) is
4.7 to 7.1 hours; but despite this, slow accumulation occurs with multiple doses.", but it takes a week for 5alpha reductase to start producing DHT again after the last finasteride dose.
Finasteride supposedly leaches into the semen so that's why you want it out of your system before conceiving.
2.) it does affect fat a little bit as estrogen levels become a bit higher, however if you're physically active it shouldn't be a problem. It won't affect muscle growth as far as I know, many buff gym guys are on finasteride.
3.) 0.2mg a day was shown to be just as effective as 1mg per this Japanese study:
(the graph shows hair density 0.2mg vs 1mg vs placebo)
http://www.ncbi.nlm.nih.gov/pubmed/15319158
At your current state you could probably even take 0.1mg and work your way up. That's what a lot of people did who did not experience sides at 0.1 or 0.2 but did at 1mg or 0.5mg. So you could try 0.1mg daily or 0.2mg every other day since your loss is quite mild to be on the safe side. Many people don't get any sides at all at 1mg but it's unpredictable and you can always increase a dose after getting used to it.
I would add Nizoral 1% shampoo 2-3 times a week to your regime as I did notice an improvement of hair texture. I don't take minoxidil but it works for some people, however anything you gain on it will be lost should you decide to stop it (some get chest tightness, shortness of breath on it, like I did). Also add 10,000 mcg Biotin, I take 5,000 mcg half a tablet in the morning and then 5,000 mcg in the evening.
Good luck sir! and don't forget to report back in 3-6 months on progress as it encourages others who are considering the jump themselves.
