As for bible translations, don't limit yourself to just one. The object of the bible is to translate into English the original language. If you want accuracy, learn the original language! That being mostly not practical to do, use different versions to study passages. There are many versions right on the internet. Many sites that will contain several versions with commentaries from several different sources. Yes, it takes longer. But from that you can see what many think and put it together yourself to decide who is closer to the bible. The object is not how popular an interpretation is but how accurately it is translated from the original. It is not the opinion of the church that you want but what the bible has to say. Do not open those bibles without prayer.
The bible does not contradict itself. If there are passages that seem confusing, then look to the character of God for clarification. The spiritual gifts can be researched pretty clearly. Read 1 Cor. 12. The whole chapter deals with that. There are no verses in the bible that states spiritual gifts have ceased. In fact we are cautioned to use care and test the spirits as there will be many false prophets which obviously means there will be true ones. They did not say to disregard all prophets.
Tongues can be misleading---follow the bible concepts not the church or a pastor. You must study for yourself, and not expect to be told what it says.
1Co_13:8 Charity never faileth: but whether there be prophecies, they shall fail; whether there be tongues, they shall cease; whether there be knowledge, it shall vanish away.
1Co_14:5 I would that ye all spake with tongues, but rather that ye prophesied: for greater is he that prophesieth than he that speaketh with tongues, except he interpret, that the church may receive edifying.
1Co_14:6 Now, brethren, if I come unto you speaking with tongues, what shall I profit you, except I shall speak to you either by revelation, or by knowledge, or by prophesying, or by doctrine?
1Co_14:18 I thank my God, I speak with tongues more than ye all:
1Co_14:21 In the law it is written, With men of other tongues and other lips will I speak unto this people; and yet for all that will they not hear me, saith the Lord.
1Co_14:22 Wherefore tongues are for a sign, not to them that believe, but to them that believe not: but prophesying serveth not for them that believe not, but for them which believe.
As for salvation--yes--you can choose to walk away from God
Mat 12:43 When the unclean spirit is gone out of a man, he walketh through dry places, seeking rest, and findeth none.
Mat 12:44 Then he saith, I will return into my house from whence I came out; and when he is come, he findeth it empty, swept, and garnished.
Mat 12:45 Then goeth he, and taketh with himself seven other spirits more wicked than himself, and they enter in and dwell there: and the last state of that man is worse than the first. Even so shall it be also unto this wicked generation
There is a difference between stumbling and falling--and staying down. We can stumble and fall, but Jesus will catch us and we ask for forgiveness. The problem is staying down. If you remain in your sins, then you certainly can be lost.
1Pe_1:5 Who are kept by the power of God through faith unto salvation ready to be revealed in the last time.
1Pe_1:9 Receiving the end of your faith, even the salvation of your souls.
Rom 8:37 Nay, in all these things we are more than conquerors through him that loved us.
Rom 8:38 For I am persuaded, that neither death, nor life, nor angels, nor principalities, nor powers, nor things present, nor things to come,
Rom 8:39 Nor height, nor depth, nor any other creature, shall be able to separate us from the love of God, which is in Christ Jesus our Lord.
2Ti 2:15 Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth.