Hi! Sorry for late answer! When I'm in vacations I really try to disconnect as much as possible.
About your first point, I already see the use of the third party services as a kind of airdrop since they bring tokens for free. Delivering them according to Steem stakes would be counterproductive as it would deter small stakeholders from accumulating SPP through use of the services.
Direct buy of SPP will be available in the future through a transaction to @steemplus-pay, whether by tip or any kind of transaction.
Hope I answered your questions