You refer to "the first "Strange fire Conference" launched in October 2013" and a new book by John MacArthur on the dangers of "strange fire". That reminded me of a book about strange fire which I read way back in the late 1990s. It's called, "Strange Fire? - assessing the Vineyard movement and the Toronto blessing" by Eric E. Wright and was published by Evangelical Press in 1996. It examined events from the 1980s onwards. I've just pulled it out to use by way of an answer.
The author attended some meetings in 1994 in Canada at Airport Vineyard Christian Fellowship. Around 700,000 people visited and went night after night to their meetings between 1994 and 1996. Apart from people in Canada and many US states, folk had come from Britain, Norway, Germany, Australia, Bermuda and Nicaragua. Vineyard leaders believed there was an outpouring of the Holy Spirit happening and said this was evidence of what they called 'power evangelism' through a revival of signs and wonders. Speakers said God was wooing them from their denominational preoccupations to go deeper into the Spirit, and that the manifestations of what they called 'being slain in the Spirit' sometimes led to being anointed for ministry, hearing the voice of God, receiving visionary revelations or the ability to prophesy. People were urged to take 'the blessing' back to their home church. Many meetings would go on into the early hours.
Supporters of that movement, and all other similar ones since, would say that spiritual revival and renewal was breaking out, and that this is seen by them as "Third Wave Pentecostalism". (Pages 15 to 23 of Wright's book.)
The answer to your first bullet-point question is that Charismatic people know what the Bible says in Leviticus about the 'strange fire' offered by Nadab and Abihu, with God striking them dead, and they are very hurt that non-Charismatic Christians (like Wright and MacArthur) claim modern-day Charismatics are offering 'strange fire' as worship. They deny that, and insist the strange events manifested in their worship gatherings are proof that God's Holy Spirit is using them to bring revival. As one example of how they see things, here's a quote from some Kansas City prophets:
"Along with James Ryle and Wes Campbell, [prophets] have brought
prophecies predicting a future war between two groups of Christians -
the 'blue coats [those who believe in ongoing revelation] and the grey coats [those evangelicals who are stuck in a theological time-warp infected by the wisdom of the world]'...
Campbell's wife, Stacey, came up to predict a great division in the
church. She foresaw a time when Vineyard adherents would be accused of
being cultic... Wes Campbell concluded his prophecy by warning, 'Do
not allow your ears, do not allow your hearts to be turned to those
that would say unto you, 'Be reasonable! Be rational! This is not
logical!' I say unto you, the natural man receiveth not the things of
the Spirit of God, for they are foolishness to him." (CRI transcripts
of Wes Campbell, Toronto Airport Vineyard, Oct. 14, 1994, pp.84, 86,
88, as in Wright's book, pp 138-4)
Your second bullet point question, "What is the Biblical basis for the calling of the Charismatic movement as Strange Fire?" cannot possibly be given a decent answer here. Wright wrote a 325 page book explaining that very question and I daresay MacArthur's book would be of similar extent and substance. After reading one or both of those books, a biblical answer would be clear, and people could make up their own minds. The scope of that second question is too vast to do justice to here. Sound-bite answers just will not do.
Jesus warned of false prophets arising, who would claim to do many miracles in Jesus' name, but whom he would disown as not having done the will of God (Mat.7:21-23). Interestingly, he did not say 'all' such miracles would be false but he did said that, "By their fruits you will know them" (verse 20). There has been enough time now to examine the 'fruits' of that Charismatic movement, to see how many prophecies were either just false, or attempts to interpret the will of God according to their theology, and how many claimed miracles were not miracles at all. There is also the test of love - for those who expect a 'war' between two groups of evangelicals, whether that's a self-fulfilling prophecy, or, indeed, a sign of cultic exclusivity and control techniques to keep people in.