Hey Divine,
One of your concerns is that there aren't many opportunities for meetings aside from Sunday. I can definitely understand your desire for frequent regular fellowship. Outside of Sunday morning services, do people there make an effort to build genuine lasting friendships throughout the week? It's good when Believers come together on Sundays to hear sound Biblical teaching, sing and pray as a congregation -- but I also believe that it's important, and even essential, for us to connect throughout the week or month and really get to know one another beyond the brief conversations that normally take place before and after Sunday morning service. Meeting up only on Sunday mornings can be a bit limited and surface level. It's great to come together, but you really desire more interaction and fellowship than that. I don't want to assume that you haven't reached out to anyone already, or that the people there don't reach out to one another. But maybe that's something you can bring up on Sunday and speak with others about. The meetings don't have to take place in that rented space. You could just meet up with a handful of people in any place that God provides.
I hear what you're saying about the Life Groups. I have a similar issue when it comes to "topical sermons." There's normally a leader over the group who picks a topic and teaches a "life principle" using various Scriptures to support the lesson. While there's certainly nothing wrong with topical teachings, that shouldn't be the whole or the bulk of instruction. When Believers come together and crack open our Bibles, we should be desiring the whole counsel of God and seek to learn the chronological history of the Bible (which is important). Not just being taught "life principles" with Scriptures mixed in to support a topical teaching. I believe that it can be a problem when Believers are taught to live by principles rather than encouraged to live by the leading and power of the Holy Spirit (I think that there is a difference). Muslims, Buddhists, Hindus, and even atheists and agnostics can live by good principles -- this is because it doesn't require the Holy Spirit to be a moral person or a principled person. But only a person who is born again can live by the leading and power of the Holy Spirit. Paul referred to this as "walking in the Spirit." The apostles didn't teach the saints to live by principles and "good moral lessons" but to abide in Christ and live by the power of God's Spirit. I can listen to a secular motivational speaker and hear about good principles. But if I want to hear how to live by the Spirit, I have to consume the very word of God in context -- taught in an expositional manner, and not quoted in bits and pieces for topical teachings.
You also mentioned that there aren't many areas to serve. I don't know what your spiritual gift is, but if it's needed where you are, your gift will make room for you. Normally spiritual gifts flow naturally and organically from the Holy Spirit. For example, if you are gifted to teach, you will find yourself in situations where you are teaching and sharing with other Believers, even if you aren't a leader in the assembly and don't have a title. You will find yourself coming alongside other Believers (maybe over the phone, over a meal, etc) to instruct them about certain spiritual things. Some of us have the mindset that we're suppose to join a church and then find a ministry where we fit in -- sometimes not realizing that the ministry we're looking for is the spiritual gift(s) God gave us. Sometimes we also overlook opportunities to serve beyond the building. Yet in Scripture, the majority of Christ's ministry took place outside, in public places, in places of residence, and so on. The same can be said for the apostles and the prophets. The Lord will show you where you are needed and orchestrate situations for you to serve. It just may not always happen where you assemble.
I won't preach at you about not forsaking fellowship, because you sound like you're in serious pursuit of Biblical fellowship -- otherwise you wouldn't have shared your concerns and reached out for counsel. I just encourage you to be prayerful and use discernment. Take your time. There's no rush. I know that there's a lot of cultural pressure to join a local church and become an official member on paper (because that's the way 'church' has been done for a long time), but try not to feel so pressured.