CELTA advice from those in the know please

[justgiveemwhiskey]

I have recently been invited to attend an interview to assess my suitability as a CELTA student. I found the application task relatively straightforward although I will admit to taking a fair amount of time researching on the internet and trawling through books. I guess the interview will reveal how many of my explanations actually made sense.
The reason for this request for advice though concerns the actual course content. In the process of preparing my application I discovered that my knowledge in certain areas still has a long way to go. Does the level of grammar skills required during the course exceed that which you will be teaching to students? I am confident that I understand the concepts an intermediate student would be studying, any higher and I think it will begin to show......
Thanks in advance for your time if you are able to reply
PS If successful I would like to teach here in Lisbon where I live, any advice on the Portuguese market?

[Tdol]

Even at the end of the course, there will almost certainly be gaps in your knowledge, so it is important to learn how to handle questions that you're not sure about and to be prepared for this. In your first year of teaching, you will find that there's a lot to learn, especially if you have aqdvanced levels.

I am afraid that I left Portugal quite a few years ago, so my knowledge of the market is rusty.