_Do temporary or seasonal employees receive different benefits and tax treatment than permanent employees?_
No they do not. Employee eligibility for unemployment benefits and tax withholding is not affected by length of employment. You may be responsible for tax and government payments and benefits for short-term, temporary, and/or seasonal employees, as long as they meet the regular eligibility requirements.
In almost all respects these employees intended only for the short-term are still employees and therefore protected by most labor and employment laws. You should still be careful of discrimination, harassment, and wrongful termination, for example.