Hi, In answer to your question "How do I make these lines parallel?"
It's very difficult and takes a long time in the iD editor, (you have to draw squares over the ways joining to the existing nodes, square up the new areas, delete the new areas, existing nodes stay squared up).
In JOSM its fairly easy to make and select all ways that should be squared up. So I've done this for you in that whole area, Changeset: 79961014 if you want to revert it.

If you need any other areas squared up just ask. Regards Bernard.

Hello and Welcome to OpenStreetMap.
Everything in OSM should be verifiable. Can you say/show the source of verifiability that the fast food outlet and the name of the building is genuine. If it's fiction could you please remove it.
Thanks Bernard.

Hi, I've removed the name building from the three buildings as I think this is inadvertent fiction.
Regards Bernard.

Hi can you say if it's 20 or 30 mph on these two roads? Thanks.

I've attached the ATM to the wall.

Hi Welcome to OpenStreetMap.
It would be great if you would square-up the buildings you've added. They'll then look much better.
I've amended the three buildings where you had building parts of differing layers/levels.

Regards Bernard.

Hi I've reinstated areas you inadvertently changed.

Hi, I've reverted the deletion of Way: Burgess Hill (33511386), also redrawn ways 666044181 and 666044184 that you inadvertently mis-shaped. I think I have removed all spare nodes left from your deletions. Please be very careful when removing or changing features, it is so easy to change other features without realising it.

Please note that by amending/correcting existing mapped features (rather than deleting and redrawing) all the previous history in maintained. Your deletions have resulted in a loss of history.

Regards Bernard.

Hello and Welcome to OpenStreetMap.
I've removed your three new named ways, (they being duplications of the existing ways), adding the new names to the existing ways. By amending the existing ways with your new data all the original history of the contributors to these ways is kept.
Regards Bernard.

Well this is a great improvement, thanks for adding the buildings. I just squared them up for you, they look neater now.

Could you please state the source of information leading you to map the monuments? I have a feeling they are fictional but wish to give you a chance to show the verifiability.

Regards Bernard.

Reverted changeset, all are features are fictional.

Please don't continue to spoil OSM.

If you need help mapping please just ask, it's fairly easy to map correctly.

Regards Bernard.

Hi Welcome to OpenStreetMap.
OSM is a live worldwide database from which maps are derived. As such all features must be verifiable and fiction is not allowed, (there are alternative sites that welcome fictional mapping). You are welcome to add genuine features and if you need help please just ask.

I have removed field and the roads drawn in the river Nene so no harm has been done.

Regards Bernard.

Hi, Welcome to OpenStreetMap.
I've changed your allotments tag from landuse=aquaculture to landuse=allotments, I'm sure this slip up was inadvertent.
Keep going there's a lot more to do!
Regards Bernard.

Hi, Welcome to OpenStreetMap.
It is quite likely that that footpath was never a public right of way, as many paths are not. Because a path is not a public right of way is not a valid reason to delete it from the OSM database. Rather you should seek to tag it's actual status.
The path can easily be seen on the Bing imagery. If it's on the ground and verifiable to other folk then there is reason for it to be included in OSM.
Regards Bernard.

No response so I've removed the crossing point

Name is changed to a description tag

Hi, Welcome to OpenStreetMap.
The tag "maxspeed:type=??? describes how a speed limit has been set into force" it does not state what the max speed is so is not much use on it's own. Please see :- maxspeed:type=*

It's better to use tags :- maxspeed=?? mph + maxspeed:type=GB:nsl_single + source:maxspeed=??? Please see :- maxspeed=*

Regards Bernard.

Hi, Welcome to OpenStreetMap.
You have tagged the whole building as being the nightclub. If the nightclub does not occupy the whole building then this is wrong. There are two correct ways to represent the nightclub, split the building, tagging only the club section as the club, or place a POI within the building preferably on the clubs entrance to the building.
Could you please make suitable amendments, if you need help please just ask.
Regards Bernard.

No response so I've removed untagged ways

Hi, no response so I've removed the untagged ways that did not seem to make a recognisable feature.