Moving a toilet-query on new waste pipe lay-out

[Chris43]

I am in the process of installing a new bathroom up stairs and changing the position of the toilet at the same time. The new toilet position is at 90 degrees to the old-I am doing this by moving a stud wall and putting the toilet against the new wall. I have two points with respect to the new waste pipe lay-out that I would like advice on:

1) I have had to extend the waste pipe. The total length of the new horizontal run of 110mm waste pipe is 1.5 m. There are 2 elbows in it. Will this horizontal run cause any problems with the toilet emptying?

2) The vent stack is now in the horizontal run-300mm before the vertical waste pipe drop (1.2m away from the toilet), so the waste flow goes past the vent stack before descending the vertical stack into the ground pipe work. Will this effect the function of the vent pipe?

Additional information: The house has had 4 toilets, 2 upstairs and 2 down stairs, but I have removed 1 down stairs toilet and capped the waste pipe. There is 1 vent stack in the house -it is upstairs. The waste pipes are internal. The new toilet is a duel flush type.

Please advise if there are any concerns or conflicts with regulations. Thank you.