EssentialPIM

If I create a new event and add a reminder I get the options of 1 hour/day/week etc.
If I create a new task and add a reminder I get the option to add a "date and time" which when selected picks the current date and time that has to be manually changed.
How do I get the same selection of hour/day/week etc. that I get in an event?

That is not possible as Tasks might not contain date/time data at all and therefore specific date/time should be mentioned for tasks reminders.

But if I create a task for say Monday at 11am then set a recurrence of every Monday and no end date. How do I set a reminder for 1 hour before each task without manually setting a date and time for each. Which would take ages.

You should set a reminder for the first task only. Once that task is completed, the next one in the series will be created with a reminder date/time automatically reflecting changes.

Ok, I'll do that and thanks for the help.

a) If I define the due date in a task detail and want to be notified of this task, I have the option to "Add reminder" with the same date as the due date. It's alright. But when I add another reminder, the choice is just the same date. I recommend adding more options to the menu (at the same time as the due date or current):
- Tomorrow
- Next week
- Next month
- Next year

b) If I tick the task completed, I recommend changing the Finishing Date to the current date and time (especially if the task does not have completed completion date)." Now I don´t know answer when I finish my task.

c) Does the application automatically delete all completed tasks without the due date?

Thanks for the first two suggestions, noted.
Regarding your question, see the Tasks settings, more specifically the "Automatically delete completed" option.