Very interesting to know this. Let me answer your questions below:

Q. Are you in generally favor or against advertising/sponsorship/affiliation on Steemit?

A. Advertising is good if it is not intrusive and complements the content. If the ad pertains to a completely different niche as opposed to the topic of the content the content creator as well as the readers will be put off by it

Q. Would it matter to you if it was graphical or based in text?

A. There is a certain level of "ad blindness" that is prevalent all over the internet so I would say that text ads could work better in the long run.

Q. Should it be an integral part of the STEEM blockchain, or left to third parties?

A. I think making it a part of the Steem blockchain would be a wise decision. Third party software integration without any connection with the blockchain could have serious drawbacks in the long term.

Q. What level of advertising would make you stop following someone?

A. Too many ads will be a put off and will trigger an unfollow.

Q. What would encourage or discourage you from placing some form of adverts in your own content?

A. Pure incentivization would be the encouragement. However, if I feel that readers have an objection to the ads in my content, or if there are too many spammy ads that will make me remove them.

Upvoted and following for more.