Home developing E6 - up to what point is it worth it?

Formaldehyde? Is this or any of the other chemicals dangerous?

Formaldehyde is now considered a carcinogen and should be treated with respect. However, remember that Formaldehyde in high concentration was used to preserve human and animal corpses and routinely handled by medical examiners for many decades. Therefore I would not freak out, if a droplet of Formalin touches your skin.