Repelenishment System-Reordering Policy-Manufacturing Policy

Dear all,
I need your help to give me a clear solution about MTS and MTO (mfg policy) relation with reordering policy. As in navision :
Replenishment system (RS) comprises:
1. Prod. Order
2. Purchase order

Manufacturinf policy (MP) comprises:
1. MTS
2. MTO

Reordering policy (RP) comprises:
1. Lot for lot (include inventory: yes/no - optionable).
2. Order (no. include inventory)
3. Fixed reorder quantity (include inventory: yes)
4. Maximum quantity (incl. inventory: yes)

my questions are:
1. if I choosed MTS and RS no. 2 , then I will use RP no. 3 & 4, I choosed MTO and RS no. 2, then I will have to use RP no. 1 & 2. Am I right ? ( I concl. these from an ERP system book).
2. If I have 5 unit item A (item A parameters are RS no. 2, MP no. 2, RP no. 1, include inventory yes) in inventory location blue. Item A used to produce item B about 20 unit (item B parameters are RS is no. 1, MP no. 2, RP no. 1, include inventory) with qty per is 2 in prod. BOM, I then use planning worksheet (PW) to generate supply order (with SO item B location is Blue), how many qty of A will I have to purchase ? lead time B is 1 week, lead time A is 3 days.
3. As far as I know, lead time in navision is offset time, that is purchase lead time first is going, then mfg lead time is the next. is this right ? does the navision support parallel lead time?
4. Why order planning needed qty of a certain item or all items is purely come from production BOM qty per times qty item to produce in Sales order (SO), though I have some stock/qty on hand (in the same location)?
5. Does the parent item parameters setting give influences to its production BOM items parameter? If I set parent item parameter different than its parts item, will the parameter subassemblies or purchasing items will have no impact anymore?



pls let me know your answers. :-k

rgds,