Thank you for your question. It’s a tough one because the Bible isn’t very specific on intimacy while dating. As a result, I can be neither too objective nor too authoritative in my reply. I think we just have to apply some common sense and spiritual sense when it comes to ethics and human sexuality.
As I talked about in my dating guide at: https://christiandataresources.com/loveandmarriage.htm, I believe that God wants us to prioritize our spiritual relationship with our partner before our physical one. Unfortunately, in most dating relationships the physical is the focal point. Oftentimes, it serves as a substitute for the more genuine and lasting form of intimacy that can only come with getting to know someone in depth over time.
How far is too far? I would recommend that people ask themselves what things they would prefer knowing that their (future) spouse has done with other people. If you wouldn’t want someone having a particular level of intimacy with your future spouse, then you probably don’t want to do those particular things with your dating partner. Remember that without binding marriage vows, it’s not likely that your current dating partner will actually turn out to be your spouse, especially in today’s society of liberal dating where most people have had many partners. So, you must always bear in mind that you may indeed be dating someone who will eventually be someone else’s spouse, and you don’t want to do something that would cause a burden for that person later. When someone knows that their spouse had very strict boundaries with other dating partners before they met, this brings a certain peace as well as enhanced intimacy (and privacy) between them, even after many years of marriage.
I once heard a pastor say that “God didn’t intend for kissing to stop with kissing.” In other words, God designed our bodies, He “invented” this sex thing, and he knows what gets people aroused. For marriage partners, kissing isn’t supposed to stop with kissing. He intends for it to lead to further intimacy (so maybe He would restrict it to marriage partners). As a result, it can easily be misused while dating, causing major challenges for the male libido. Ironically, after marriage, this same libido can lead a man to great intimacy with his wife, on many levels: sex, love, spirituality, prayer, and living for Christ.
Now, that being said, I realize that this seems quite restrictive. Based upon this, one could even build a valid case that holding hands should be avoided because that could lead to kissing, etc. I also know that this would seem ridiculous to most people today, especially when sensing physical attraction to a potential mate. So, most people aren’t going to respect such boundaries, but this doesn’t change the fact of what God thinks on this subject.
I wish I could be more helpful, but I think that you just have to make sure that you’re listening to God. This includes a strong prayer life and Bible study. We breathe out prayers to Him, and He shares His mind with us through His Word. Just like with the other aspects of your life, if you’re in tune with God’s thinking, you would want to stop short of anything that would cause you to feel guilty.
I hope this helps, and again, thanks for the bold question.