H1B Transfer and currently H1B Amendment in process

HiI am working with Company A and I -140 approved. I got project on Sept 2017 and company A did H1B Amendment but Project is over in 3 month and we got RFE for Amendment on Jan 2018.then after I got other project on 15th Feb 2018 thru Company A ,so Company A did H1B Amendment again without Client letter and Company A withdraw my previos Amendment ( which I got RFE)Now I got new project 24th April with Company B and Company B wants to do H1B Transfer with their payroll. Query is below : 1.)Can I do my H1B Transfer with Company B if my second Amendment is in process with Company A2.)Is it safe to do H1B Transfer ? how much risk to do transfer visa H1B ?3.) is it affect my I-140 with Company A ?pls help me out .appreciate for your helpThanks