Dose the orthodontist sometimes have to remove some of your teeth to straighten them out?

Yes. while we create space for crowded teeth in many ways such as 'slenderizing' teeth and widening pallets, sometimes teeth do need to be removed if crowding is too severe. Typically this is done to both sides to retain symmetry.
Sometimes/Depends. The removal of teeth may be required to correct a malocclusion if the crowding is too severe for expansion. Removal of primary teeth may be indicated to aid in eruption of permanent teeth or to help avoid possible impactions of permanent teeth. Each orthodontic case is different, so it is importnat to disucss the rational with the doctor based on his diagnosis and treatment plan.
Yes. Depends on the size of the teeth, size of the dental arches and the particular orthodontic problem.
Absolutly. It is very possible that your orthodontist may recommend extractions this occurs when you h e more tooth structure too the size of the jaw then two or four teeth usually need to be removed although not the first option but sometimes becomes the only option.
30% yes. 30% of all orthodontic patients do not have enough jaw support for all of their teeth, or there are positional anomalies that are best resolved with some reduction in tooth mass. It's an engineering project, and orthodontists are best trained to manage the bio-physics involved. The up-side is that 70% of patients don't require extractions. Hope you're one of the lucky ones.
Certainly. The removal of teeth is sometimes necessitated in orthodontics to resolve significant crowding or protrusion of teeth. Extractions for orthodontics is a time-tested, evidence-based approach when they are needed. Only your licensed orthodontic specialist can tell whether extractions are recommended for your situation.
Sometimes. If the clinical evaluation and analysis of your records indicate there is insufficient space for all of your teeth to fit into each respective jaw, the orthodontist may recommend the removal of specific teeth to create space to correct the malpositioned teeth.