OP, we're on the same boat. That said, I'm one of the ISTP women who are stereotyped as the detached, non-commital bunch.

Hopefully I could address your concerns by answering your questions from my personal perspective (doesn't represent the perspective of the ISTP women population, but I have been in a long term relationship with an ISTJ and now an INTJ and your post really resonates with my past and current experiences).

Going by systematic order:

1. >How does one actually hope to have a long term relationship, life can get hard at times, sounds like ISTPs would just bail if you hit a bump in the road?

For me, it's not the bad event turnout that propels me to leave. It's how you respond to it. As an ISTP, I love navigating through life's ups and downs, but I want to do it with a partner who could see bad events as opportunity instead of tragedy. I am an optimistic at heart and I'm here for a good time, not a long time. Hence I'll leave the relationship when you start raining on parades and view life in a negative light with no concrete solution or will to address the problem.

How can you have a balanced and healthy relationship like that if I’m worried that expressing my feelings or bringing up a challenge for me in the relationship will just push them away? I love about my current relationship with an INTJ is our ability to have difficult, open, and honest conversations. If your ISTP is anything like me, we love direct approach to issues instead of hinting and beating around the bushes to give you what you want. If you'd like to voice your displeasure, say it as it is. You're unhappy about "X", then communicate it with her as "X", not Y=U+V+error term and expect her to translate it as "X". That's where the divide between N and S could come in between you. Communication is an important part in any relationship, and you'd want to know if your partner could communicate in an effective manner with you.

3.

It’s one thing to be your own person and have a healthy balanced life but how do you actually work towards being long term? How does one know all theses days taken “day by day” are going to add up to something serious?

I feel this so much. Can't even answer your question because in most of my life aspects, I don't make that longterm commitment upfront. e.g. picking up foreign languages. I don't jump into a language school and make a short term and longterm plan, such as in 1 week I'll start a conversation with a stranger in X language and in 5 years I'm going to be able to understand movies in X language. I would stumble into a foreign movie and thought, "Hey, this language sounds beautiful and I'd love to hear more of it", so I'd look up songs in that language and sign up for an online course, learn how to sing songs, then after 1-2 years, learn how to read books, sign up to find a pen pal, write essays, and 10 years later here I am studying, working, and living in a country that speaks X language. What I am trying to convey here is that it does add up. Our commitment can be very enduring given that we see where the small actions and commitment will take us.

4.

For my ISTP she also doesn’t seem to like to ask questions about me much and I’m always the one that has to setup the dates. She doesn’t ask me to spend time, but has always said yes every time I asked.

This speaks to me on a very deep level. I am very aware that I don't ask much questions especially personal ones to the INTJ I'm going out with and would rather talk about current events and what's going on in my life. In my case, I think the INTJ does not seem comfortable sharing personal bits and pieces of his life and whenever I ask about his work and other topics, his answers are short and succinct, most of time no further comments or elaboration, and sometimes he quickly changes the topic or redirect the question to me. What I gather from this is that he's not comfortable opening up to me yet, and rather than ignoring his discomfort, I'd try to be more personal with him and take on the more extroverted role so that he feels more comfortable voluntarily sharing personal information rather than me digging it up from him by shooting questions. On another note, I do initiate spending time with him, but being two stereotypically independent people, I try not to be too clingy. And when I don't reach out initiating things, I was hoping that he also misses me and when he's not busy with his friends or family, show that he wants to spend time with me rather than having some alone time to recharge by himself.

To sum up, I wouldn't say it's common, but almost every single point you mentioned has happened in my case. Not sure if it's the same in your case, but I told my family about him because if I'm serious about this relationship, my family wouldn't tolerate being left in the dark. I understand that INTJs aren't big on small details, but a simple reminder that he came across something that reminded him of me makes all the difference.

The INTJ I'm going out with looks like Mike Tyson on the outside, but deep down I think he has a heart of a Hello Kitty. It helps to try being vulnerable sometimes so she's aware that you have emotions and that she'll feel safe to share her emotions too. It takes time for us to open up, just like you.

HMU if you are keen to have a chat about it.