item dropped with execute at destination should work. the objects interaction position needs to be specified in the properties section for each object, & the position needs to be inside of the way system border otherwise the playable character can't reach the position, which means that it won't ever execute the actions.
You can publish for windows, mac, linux, & html5 with the indie (single/multi-user) license. You don't need a mac to export for mac - though it's recommended. If you export for mac via a windows machine, make sure you don't open up the file it generates, on your windows machine as it will likely corrupt it. It looks like a zip/rar file on windows, but it's not. Just zip/rar it up or upload as it is as it's a dmg file which is like an ISO image file.
I would recommend looking into the basic version of the mac mini (one without all the bells & whistles) if you ever have some spare cash floating around. I think they cost around €400-€500 - less if you look for refurbished ones. Those things aren't super powerful, but they are more than powerful enough for developing & playing Visionaire made games.
I don't know about exporting for Linux as I'm not a fan of it & don't have it installed on my pc or laptop.
There's some information here
about exporting for different platforms.
One last thing... in regards to html5, you can distribute html5 games as freeware, or with ad-based monetization, or you can distribute to Patrons/Pledges via self-crowdfunding/support sites like Patreon. To actually sell the rights for an html5 game to a publisher or company, such as Facebook, then you will need to purchase a professional license (which is a per game/title, but doesn't need to be acquired until needed).