A few tools I wrote along those lines:
Individual notes:
http://www.renoise.com/tools/note-properties
Using Automation lanes:
https://forum.renoise.com/t/new-tool-2-8-velocity-pan-delay-automation/39441
Setting selection in pattern:
https://forum.renoise.com/t/new-tool-set-meta-values/33933
I agree this really needs addressing natively in renoise.