GD V2 Upgrade | Short Code | Clear DB

Tried short codes from V1, only few working in V2?

As my schedule is tight now, V2 seems very different to V1. Could you confirm the following?

1. Can V1 be upgrade to V2 easily without risk? If so, I can finish off V1 production and upgrade when complete. Due to schedule, I am more comfortable to work with V1 at this stage. V2 GD setup panel is completely different to V1 which I have to study again, especially section like DESIGN in GD setup.

2. What are the major improvement in V2? Performance? Features? Visual?

3. How to clear all data completely in V1 (eg listings, location records etc but without removing defined categories)? V1 is pretty much completed, however, I need to clean up all data from DB and reloading new data. I find that if I truncate table in MySQL, some related data in other table still exists. Tried to tick the remove data when un-installing GD core (without removing add-ons) but doesn’t seem working.

Thanks

Sam