Is it proper to mix alkaline and acid products together?

Answer 1

Yes. There's no harm in doing that. It constitutes one of the fundamentals of analytical chemistry; mixing an acid and a base (alkaline) gives you as a result a salt and water. Take a look at this example: HCl+NaOH--> NaCl+H2O
When you add Sodium Hydroxide to Hydrochloric acid it gives you a salt (in this case table salt) and water as a result.
Hope this helps :)

Answer 2

This is one of the most important chemical reactions of all, and is called neutralisation. Look it up!