Do I need to file form 709? Any tax do I need to pay or can lifetime exemption can cover it?

My status is as below 
1. I hold L1 working visa (my wife hols L2 visa), we stayed in US for almost whole year, none of us is a US citizen or permanent resident 
2. we hold an joint checking account 
3. we always file joint tax return 

I transferred (gift) some money to my farther and friends 2016 via the joint account, as below
1. wire transferred $18,000 to my farther oversea who is not an US tax payer 
2. transferred $10,000 to friend A (after he cam to US) who hold an H1 VISA and was came to US on Oct 2016, via online banking
3. transferred $20,000 to friend B (after she cam to US) who hold an L1 VISA and was came to US on Oct 2016, via online banking
4. transferred $5,000 to friend C who hold an L1 VISA and stay in US for almost whole year, via online banking

I did some search on google, looks like I have $28,000 exclusion for gifts for year 2016, so my question is 
1. Can these transfers/gifts consider as gifted by my wife and me together?

2. Do i need to file form 709 on 2017, each transaction not exceed $28,000 but total of them exceeds 

3. If I need to file 709, since I only hold an working VISA but not an citizen or green card holder, can I use life time exemption (looks lie $5.4 million, I never used it before) to avoid pay tax for those gifts?