There is absolutely no problem calling the QF recruitment team. In fact, your application is probably more likely to be processed there and then if you do call. There is a massive backlog because of all the applications received and it certainly isn't frowned upon if you call to check the status of your application - just approach it sensibly and you'll be fine.
The UK base is only for cabin crew. Qantas pilots are all based in Australia and that's the way it is going to stay (for the moment).
The phone interview doesn't go for very long and you will be asked about your history, experience and some stock standards questions (no, I won't tell you what they are). You will be asked your height (163 to 183 cm) and regardless of how cunning you think you are, we do check and although you might get an invite to the assessment day, you will be automatically knocked out and not invited to interview once we have checked your height.
There is no upper age limited for Qantas. Published or unpublished. Providing you are medically fit and successfully pass the interview and training components, you will be employed as crew.