Tbh there’s no ‘grinding’.
As I explain here:
The MAXIMUM number of likes you “need” to start posting at level 2 is 1. And 1 given. You only need 30 given and 20 received to get to level 3 but getting to level 2 requires 15 days and level 3 needs 50.
If you’re a semi-active poster, you’ll probably rack up the necessary likes over the course of 3 months I’m sure. Not counting the ‘like mine’ thread I got about 20 likes from genuine posts already.
There’s also no benefit to making new topics just to “farm” the trust level system, it only asks for X number of replies to existing topics.