In my experience giving and getting readings over the last 8 years, I believe free will is often an excuse for weak psychics who want to justify their failure for not making solid predictions.
Free will does make something happen sooner or later-- we all can reach our destined paths through countless of ways. But if something is destined to be, it will be and if it's not it won't happen at all. Free will can only change its timeframe.
Freewill can also be applied to smaller predictions e.g will I go on that family trip on Friday? where decisions are taken almost spontaneously.
But for all bigger life events e.g the person that you'll have a long-term relationship with or if and whom you'll marry, and if you'll have children or what is your ultimate career path, there is no free will excuse here and I wouldn't personally believe any psychic that tells me otherwise. If they can't predict a big event like this and give me the free will excuse, it means that they were simply not connected.
Ultimately, we can delay or speed up certain outcomes or maybe change the ways these happen but some things are predetermined ever since our birth and no amount of "free will" can totally change this.
This is exactly what I came here to say.
There are certain things that your soul came here to do - the bigger life events, like you say. So, if you are meant to marry that person, or have that house, or work with children, etc... then those should be things that a psychic can pick up on and that would not change in any way other than the timeframe it takes to get to those moments.
I was thinking about it today in regard to my POI... I used to fret about when to contact/text, if I didn't whether it would change things drastically, etc... the way I look at it now, I go mostly with my gut. I consider how I feel, what he may be feeling, etc and go from there. If things are meant to work out long term, they will!
I also think the more worry energy you put into things the more you can change the vibe/connection. But even so, I think if you are meant to be with someone this won't make a huge difference in the long run.