I have heard many times that reading Gita without a teacher can be dangerous. Does it mean reader can take serious action if influenced strongly in wrong direction.
Many people here are aware of the fact that Sruti(the Vedas) should be learned and studied only under the guidance of a Guru.But the necessity of a Guru is not limited to Veda study only.
All the other Hindu Scriptures, like Smritis(Dharma Shastras),Vedangas,Puranas,Itihasas etc, are also to be studied under and learned from a Guru only.
A twice-born (pupil) should study the Dharma S'astras under- the guidance of his preceptor for- learning the rules of decorum and cleanliness (both mental and physical), and: do whatever is beneficial to his, master. (25)
Then the best of Brahmanas should study the Vedas, histories (Itihasas), and the kindred branches of knowledge ( Vedangas), give instructions to his own pupils, and feed the good Brahmanas. (4)
Vyasa Smriti ,Chapter 1,Verses 4, 25.
[Or, he should do it] in the first part of the first day of the month of Magha. After this, the twice-born ones should study the Vedas in the light fortnight. (57) In the dark fortnight, a person should study the Vedangas and the Puranas. Both the teacher and the pupil should carefully avoid the [following] periods,, when no Vedic studies should be prosecuted
Usana Smriti,Chapter 3.
The danger of learning Mantras, Scriptures on one's own from books or internet pages is explained in quite detail on this page: Kamakotimandali.org-Diksha Prakasha .
pustake likhitAnmantrAnAlokya prajapanti ye | brahmahatyAsamaM teShAM pAtakaM parikIrtitam || [Badabanala Tantra]
This instruction is of special relevance in the current days where people pick mantras from books or web pages and begin recitation. There are procedures described in the Shastras to pick mantras from Tantras by choosing Devi/Mahadeva as Guru but is only an Apaddharma. That cannot be considered as a universal rule. Moreover, one who has studied the shAstras and has the necessary power of discrimination alone can undertake such a practice. These days, when most ward off the need for traditional learning and resort of crash courses or counter every shAstra pramANa with hollow statements such 'Devi knows best! She wanted me to recite the mantra and hence she made me find it', it becomes even more important to understand the pre-conditions for mantra grahaNa. Devotion is an aspect of upAsanA but not upAsanA itself. Moreover, pure devotion is not a commonality in Kali Yuga. Also, adhikAra or qualification for upAsanA comes only through Diksha
Now,Bhagvata Gita is part of an Itihasa(the Mahabharata) but it is an important Hindu Scripture because of its far-reaching philosophical implications.
And, since the very nature of the text is philosophical, its all the more needed that it should be studied under the guidance of a Guru who knows the purport of all its verses fully.
Now,suppose if you give a Scripture X to N number of persons to read and understand, chances are that they will interpret it in N number of ways.And the reason is simply that they are all in different levels of consciousness.
So,its better to learn all Scriptures(not just the Vedas) from a Satguru.By this process your own consciousness-level will also expand and you will have newer and better interpretations of the Scriptures that you have already read.
So,not sure if it will be dangerous,but it will be misleading for sure.
This usually because people misunderstood some of the things mentioned in Gita. To understand terms in Gita it is required that a person should have some real life experience. That's one of the reason it has been said that we should do study or understand it with the help of Guru, but its doesn't mean that with Guru you will understand everything correctly. Don't limit yourself.
Please go ahead and read Bhagvad Gita , I firmly believe this maha mantr should be made compulsory in all schools upto college (and beyond).
Interpretation "n" times agreed and that's the beauty about Hinduism, (which had been misinterpreted by westerners and believed by people who have more faith in them then their own people) Bhagvad Gita will show you the path you deserve for your growth (even genetically identical twins have different path) so go ahead and read (Personally I believe Hindu scriptures should only be read in Sanskrit/Hindi. English or transliterated scripts should be forbidden) Read the Mahamantr multiple times (better) if you feel like. I will go as far as saying every religion (yes every) has originated from Hinduism.
Hinduism shows infinite path to achieve but goal is similar rising above over many cycles (of life and death) and ultimately releasing ourselves. Another point to consider is even if we are not released by our karm then also at the end of 100 Brahm years we all merge into ONE.
Follow the path : Keep doing your karm and dont focus on results let them be whatever they are, you are here to perform and not results