As @Andra indicated, trends are based on more than just your location. From the Twitter trends FAQs:
Trends are determined by an algorithm and, by default, are tailored for you based on who you follow, your interests, and your location.
Not really. These sites do have an API, but they're more limited than the SQL access you get with SEDE. There may be third party tools that utilize the API to get more powerful data out of it, but which one of those comes closest to what you want to do is out of scope for this forum.
The APIs in question can be found here:
The feature is still available, though unofficially. Just set up a browser extension switching Twitter to the pre-2019 design:
for Google Chrome / Opera / post-2019 MS Edge: https://chrome.google.com/webstore/detail/goodtwitter/jbanhionoclikdjnjlcmefiofgjimgca
for Firefox / TOR: https://addons.mozilla.org/en/firefox/addon/twitterfix/
...and the Import/...