To Henna or not to Henna and other Questions

This was actually a private message to CN but I thought I would post here to see if I could get any input.

I've been devouring posts about hennaing and searching online for info. My reason for hennaing are to: color (cover) the gray and strengthen my hair. I have thyroid disease which has caused thinning; also, I am perimenopausal. Lots of hair comes out when I shampoo and/or cowash. This could be due to the hyperthyroidism OR lack of knowledge of dealing with curly hair that I've had all my life.

I am reticent about doing the henna because of all my uncertainties.
(1) Will it loosen my curl in the front where my hair is thinner. (OH I texturized a year ago around this time; I do it every other year to loosen my natural curl which is 3a [I think]) but am considering not doing it anymore because I think the thyroid disease is impacting how the relaxer takes.
(2) In your (CN's) tutorial you didn't let the Henna sit and I thought it needs it to sit for dye release over night, but I've read Reshma has FAST dye release (15 minutes).
(3) With the amount of gray hair I have, how often will I have to Henna - I'm busy with work, school, 15yo teenage girl, and new hubby.
(4) Should I use Reshma or another brand.
(5) I have 200 g Reshma Henna (I purchased from local Indian store) and 200 g Indigo from Ayur Natural Beauty. My hair is CBL (yay using lingo ) when curly - below shoulder blade length when blowdried - is this enough Henna and indigo. How much indigo do I add to the Henna? For the second single app of Indigo how much do I need?
(6) When I do the 2nd application of Indigo after the initial "Hendigo" ( I made that up) application do I wait til the next day or apply afterwards.
(7) My local Target did not have the Aubrey DC so I purchased Paul Mitchell's Humectress. I also have a little Mixed Chicks DT left. Are either of these good?

Hi,

I use body art quality henna, purchased thru mehandi.com. It's fabulous. My hair is fine in the top as well. My hair comes out extremely soft and I like the red tinge that my gray hair has when I'm done. The brown/black hair doesn't show the henna of course because there are no chemicals in true, natural henna. The website gives you thorough instructions on mixing and application. Yes, it should sit over night, to be sure to bring out all the properties in the mixture.
My curls are more defined after I henna and it's a great conditioner.

Thanks MimNatural! I can't wait to do it. Someone posted the use of amla and brahmi to cover the gray versus using indigo.