Can I temporary disable/remove the cookie bar from the store front end?

Yes, in the application settings the first option you will see is to enable/disable the app from your store frontend.

How can I change the Look & Feel of the Cookie Bar?

On the application dashboard, you will see the settings tab in the header menu, from where you can customize the cookie bar (Display section).

You will also find a 'click here' button from where you can navigate to bar customization.

Is there any way to modify the text which is displayed in the bar?

In the application settings --> Display, there is an HTML editor option from where you can modify the text, as shown here.

Can I customize the bar's colors?

Yes, there is a color selector option available in 'Settings' under 'Display' --> "Colors" as shown here.

Why is the corner pop-up disabled when the checkbox ("Allow customers to manage their data") is checked and the bar is shown?

If we do not allow our customers to manage their data, the corner pop-up functionality does not make any sense.

Is there any option available to clear Browser Cookies Lifetime so that this bar can appear on the store frontend of the user who's cookies are expired?

In the application setting under the 'Settings' --> 'General'  there's an option available to set the Browser Cookie Lifetime in a number of days, as you can see here

I want to change the position of the Cookie bar for Mobile & Desktop device.

In the application settings under the 'Display', there is an option available to set the position of the bar appearing on the store frontend on desktop & mobile devices, as you can see here. 

Can the Cookie bar only be displayed for the users who are accessing the store from the EU region?

There is a checkbox option available in the general settings page, where you can select the region as shown here.

Are there any manual coding steps available to install the app?

No, there are no any manual coding steps you need to perform to configure the app.