>>5 I may be wrong, but in my perception I saw it as an indirect from of asking for help, whatever the case. Quoted from the top: "AND I'm unsure if this means him and I are dating now??"
>>6If you both are completely positive and sure about your feelings for one another, then yes, ask him out. It could just be "indirect" (reference from above) like sending something along the lines of, "So... are we dating now or...?" It will obviously be awkward, hence the "...'s", but I'm sure if you really like each other truly, it will be fine. From my past experiences it worked well.
But, Hitomi, keep in mind that if you two get "too serious" about dating each other, and then break up, you may not be as close of friends as you were. Unless you absolutely trust him to forgive you whatever the reason, make sure with him that you'll still be friends afterward. (This is only in the case that you ever break up, which sadly is likely)
I'm not trying to discourage you from dating him, it's up to you. If you have a chance at a healthy love, go for it.