In some cultures drums have a sacred significance (e.g. Native Americans).
In European derived culture (most US parishes), drums are a secular instrument and evoke secular impressions in us, and therefore do not meet the norms of inculturation, and should not be used.

There is no Church document specifying applause as an appropriate liturgical response to music, singing, homilies, or announcements of gratitude by the presider. The only approved custom of applause of which I am aware is as a liturgical response to a newly-ordained priest as a sign of the congregation's support for the new priest.

Although the Church does not explicitly state that applause is generally inappropriate at Mass, that may be because such a stricture used to be enforced by Western society. As a matter of etiquette in Western society, it used to be severely frowned upon to applaud in church because church services are worship offered up to God and not entertainment to be critiqued by the assembly.

Now that society has generally lost the sense that applause is inappropriate in church, I suspect that the Church may soon have to speak on the matter before people take the idea to its logical conclusion and begin to boo when they are insufficiently entertained at Mass.

There is a difference between rhythmic clapping and applause. If a particular hymn lends itself to rhythmic clapping, it is not wrong for a congregation to do so.

For the most part, hymns that require rhythmic clapping really shouldn't be included during a Mass or other eucharistic liturgy because they tend to be raucous, distracting, and not conducive to drawing the congregation's attention to Christ in the Eucharist. But, in cultures in which rhythmic clapping is an authentic form of worship, I cannot presume to say that it is impossible to worship while it occurs. I can only say that this is not generally the prevailing culture in the U.S., or in many countries with a similar cultural background.

Actually, there was a prohibition issued by Rome in the middle of the 20th Century about motion pictures in Church. It would be interesting to know if Rome considers that still in force, and whether it would apply to audio/video equipment. It has never been rescinded to my knowledge.

Two points, the GIRM tells us what belongs in the sanctuary, and by silence what does not. No permission for a projection screen is contained in any Church document. Also, since the use of recorded music remains forbidden (the liturgy is something alive, real, not dead and artificial), I would think recorded or displayed words would also be.

In general, I think it is a terrible idea that reduces the power of the proclamation of the Word to efficiency of communication. God converted thousands through the poor speech of St. John Vianney.

I've heard the song and think it lovely. The questions asked throughout the song are perfectly fine meditations on what Mary's knowledge of her Son and his mission may have been. There is no need for Catholics to believe that Mary knew everything going in. She is honored for her faith, not her knowledge, and as the author of Hebrews says: "Now faith is the assurance of things hoped for, the conviction of things not seen" (Heb. 11:1). Luke also notes that Mary often pondered things in her heart (Luke 2:19), which indicates that she grew in understanding, just like anyone else.

The only lyric in the song that is ambiguous is where the singer asks, "Did you know / That your baby boy has come to make you new? / This child that you've delivered / Will soon deliver you?" This can indicate that Mary wasn't immaculately conceived; but it can also be understood to mean that the Crucifixion, by which Christ won the grace given to Mary anticipatorally in her Immaculate Conception, was still in the temporal future when Mary had just given birth. Given the possibility for confusion though, the song should not be played during public liturgies.