Questions on Nawaafil Salah, Ghusl, Zaydi Imams, and Zakat

السلام عليكم و رحمتله و بركاته و رمضان مبارك
May the peace, blessings, and mercy of Allah SWT be upon you brothers and sisters in Islam.

As a recent follower of the Zaydi Shi'a Madhhab, I have the following questions:

1) Are the nawaafil supererogatory prayers the following?:

2 raka'ahs before salat al-Fajr
2 raka'ahs after salat adh-Dhur
none after salat al-Asr
2 raka'ahs after salat al-Maghrib
3 raka'ahs (including Witr) after salat al-Isha

Also, is the Tahajjud (salat al-Layl) considered part of the supererogatory prayers? If so, how many raka'ahs?

2) I noticed there was a post on the method of ghusl but it appears there were two narrations that were slightly different. May you please provide a step by step summary of the method of Ghusl beginning with niyyah (intention)? Also, is istibra (urinating according to Twelvers) done before performing the ghusl? And is the wudhu done as a part of ghusl similar to what Sunnis do for their ghusl?

3) Is there a current Zaydi Imam who has made the call (da'wa) to be obeyed by Zaydis? Or is there still no current Imam yet?

4) Is Ali ibn al-Husayn Zayn al-Abideen (as) considered a Zaydi Imam? Is he the fourth Imam?

5) Since there are no Zaydi sheikhs or mujtahids in the United States of America, is it acceptable to pay Zakat to a Sunni Masjid? Also, do Zaydis pay khums as the Twelver Shi'as do?

I thank you for your patience and contributions to translating Zaydi books in English. May Allah SWT pour blessings upon you and your loved ones.

Thank you IRS for replying to my post and for the work you do. May Allah SWT reward you for it.

I have follow up questions to my first inquiry and a follow up question to my fifth (last) inquiry.

1) What is the method of performing the supererogatory (nawaafil) prayers? The adhan or iqama does not need to be recited right? Does the tauudh and oriental supplication need to be recited before making intention to pray each nafl salah? Should each supererogatory prayer be grouped in two raka'ahs with a tashahhud, salawat, and tasleem in every second rak'ah of nawaafil?

5) Just to confirm, may I pay zakaat online to a Sunni Masjid that I attend and khums to a 12er Shi'a Sheikh that knows how to distribute the khums? I ask this because from what I know Sunnis do not collect khums and few 12er Shi'as collect zakaat. Also, since there are no Zaydi Shi'a Sheikhs that I know of in the U.S. state of Georgia (where I live), I suppose the above are my only options for fulfilling the religious obligations of zakaat and khums.

Thanks for your patience and assistance.

You're welcome IRS, I enjoy learning about the school of Ahlul Bayt (as) and how I can improve as a Muslim that follows the Zaydi Madhhab.

I forgot to ask you some more follow up questions to my first inquiry. Specifically, the time to pray the supererogatory prayers. Are we to pray them after the adhaan of the obligatory prayer and before the iqama? For instance, would I pray the 8 + 2 nawaafil before fajr after the adhaan and before the iqama of fajr salah? Or would I pray the nawaafil salah before the adhaan of the fajr prayer (in this case)? Also, are the suras to be recited in the nawaafil salah audible for the audible prayers (Fajr, Maghrib, Isha'a) and silent for the silent prayers (Dhur and Asr)?

Thanks again for your assistance.