Please read through this - Managing Transaction Logs[/url] and http://www.sqlservercentral.com/articles/Transaction+Log/72488/
3)Will my data get effected if I create new similar name files and delete previous one after backing them up?
Other than the fact that it'll result in the database being marked recovery_pending and you needing to restore a full backup to get it accessible again, no.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability