Retirement tax questions

No, do not complete Form 4852.  This is reported on a substitute 1099-R. 

To enter foreign pension in TurboTax online program, you would NOT treat it as "other income," rather, you will create a mock form 1099-R.

On sidebar 

1. Select Federal 
2. Wages & Income 
3. Select Wages and Salaries, or Revisit 
4. Scroll to Retirement Plans and Social Security
5. Select the type of income.
   1. IRA, 401(k), Pension Plan Withdrawals (1099-R)
   2. Social Security (SSA-1099, RRB-1099)
   3. Canadian Registered Pension Income
6. Get Ready to be Impressed - Continue
7. Select [Change how I enter my form]
8. Select [Type it myself]
9. Who gave you a 1099-R?  Select and continue
10. You will post your information the best you can and continue through the interview 
11. If your foreign issue does not have an ID number, you can try entering nine 9s.
12. You will come to a screen: Do any of these situations apply to you?
13. Select I need to file a substitute 1099-R.
14. Continue until you complete the process.