1. The normal understand is gain is strict, renew is more lax
2. None. I won't even think of using 7k miles for lounge redemption using the 0.1 HKD per AM valuation. Search for a card for free lounge access the way to go (e.g. Citi Rewards)
3. Soft landing means DM > GO / GO > SL
4. They have every right to demote you from MPC GR to AsiaMiles but I never see that reported here yet

BTW please consider change your title to better fit your content, and to be honest I don't expect you to ask these question as you have been here reasonable long enough