What are Gregor's concerns in Section I of The Metamorphosis? To what degree would they differ if he had not been transformed into an insect?
It seems that whether Gregor awoke in his insect form or in his human form, his concerns would be very much the same. Despite waking up to discover he had turned into an insect, Gregor immediately begins to think of how much he would like to quit his job.
Gregor is concerned with being an insect but only because of how it is affecting his ability to get out of bed and get to work on time. In struggling to get out of bed, Gregor is more worried about bothering others (his family) than he is about his own condition of being a giant insect:
His biggest worry was the loud crash he would not be able to help making, which would probably cause anxiety, if not terror, behind all the doors. Still, he must take the risk.
When the chief clerk arrives to inquire about Gregor's absence, Gregor's concerns and thoughts become fixated on his job and his duty to support his family. When his sister starts to cry, Gregor supposes that she is upset because Gregor won't open the door and is in danger of losing his job. Gregor tries to put the chief's (and his parents') mind at ease because he is concerned about losing that job that he hates; he still thinks he can catch the next train as long as his appearance isn't too shocking.
Even when Gregor realizes that his voice no longer sounds human, and after he witnesses his family's horrific reaction to his appearance, he still tries to tell them that he will be in to work. He says to the chief clerk:
One can be temporarily incapacitated, but that's just the moment for remembering former services and bearing in mind that later on, when the incapacity has been got over, one will certainly work with all the more industry and concentration.
If Gregor had awoken in human form, but been a little sick and unable to get out of bed, his concerns would have been the same: feeling pressured to get to work to support his family doing a job that he disliked.